1
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Akhgari A, Michel TM, Vafaee MS. Dendritic spines and their role in the pathogenesis of neurodevelopmental and neurological disorders. Rev Neurosci 2024; 35:489-502. [PMID: 38440811 DOI: 10.1515/revneuro-2023-0151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 02/02/2024] [Indexed: 03/06/2024]
Abstract
Since Cajal introduced dendritic spines in the 19th century, they have attained considerable attention, especially in neuropsychiatric and neurologic disorders. Multiple roles of dendritic spine malfunction and pathology in the progression of various diseases have been reported. Thus, it is inevitable to consider these structures as new therapeutic targets for treating neuropsychiatric and neurologic disorders such as autism spectrum disorders, schizophrenia, dementia, Down syndrome, etc. Therefore, we attempted to prepare a narrative review of the literature regarding the role of dendritic spines in the pathogenesis of aforementioned diseases and to shed new light on their pathophysiology.
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Affiliation(s)
- Aisan Akhgari
- Student Research Committee, Tabriz University of Medical Sciences, Golgasht Street, Tabriz 5166616471, Iran
| | - Tanja Maria Michel
- Research Unit for Psychiatry, Odense University Hospital, J. B. Winsløws Vej 4, Odense 5000, Denmark
- Clinical Institute, University of Southern Denmark, Campusvej 55, Odense 5230, Denmark
| | - Manouchehr Seyedi Vafaee
- Research Unit for Psychiatry, Odense University Hospital, J. B. Winsløws Vej 4, Odense 5000, Denmark
- Clinical Institute, University of Southern Denmark, Campusvej 55, Odense 5230, Denmark
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2
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Perdaens O, Bottemanne P, van Pesch V. MicroRNAs dysregulated in multiple sclerosis affect the differentiation of CG-4 cells, an oligodendrocyte progenitor cell line. Front Cell Neurosci 2024; 18:1336439. [PMID: 38486710 PMCID: PMC10937391 DOI: 10.3389/fncel.2024.1336439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Accepted: 01/24/2024] [Indexed: 03/17/2024] Open
Abstract
Introduction Demyelination is one of the hallmarks of multiple sclerosis (MS). While remyelination occurs during the disease, it is incomplete from the start and strongly decreases with its progression, mainly due to the harm to oligodendrocyte progenitor cells (OPCs), causing irreversible neurological deficits and contributing to neurodegeneration. Therapeutic strategies promoting remyelination are still very preliminary and lacking within the current treatment panel for MS. Methods In a previous study, we identified 21 microRNAs dysregulated mostly in the CSF of relapsing and/or remitting MS patients. In this study we transfected the mimics/inhibitors of several of these microRNAs separately in an OPC cell line, called CG-4. We aimed (1) to phenotypically characterize their effect on OPC differentiation and (2) to identify corroborating potential mRNA targets via immunocytochemistry, RT-qPCR analysis, RNA sequencing, and Gene Ontology enrichment analysis. Results We observed that the majority of 13 transfected microRNA mimics decreased the differentiation of CG-4 cells. We demonstrate, by RNA sequencing and independent RT-qPCR analyses, that miR-33-3p, miR-34c-5p, and miR-124-5p arrest OPC differentiation at a late progenitor stage and miR-145-5p at a premyelinating stage as evidenced by the downregulation of premyelinating oligodendrocyte (OL) [Tcf7l2, Cnp (except for miR-145-5p)] and mature OL (Plp1, Mbp, and Mobp) markers, whereas only miR-214-3p promotes OPC differentiation. We further propose a comprehensive exploration of their change in cell fate through Gene Ontology enrichment analysis. We finally confirm by RT-qPCR analyses the downregulation of several predicted mRNA targets for each microRNA that possibly support their effect on OPC differentiation by very distinctive mechanisms, of which some are still unexplored in OPC/OL physiology. Conclusion miR-33-3p, miR-34c-5p, and miR-124-5p arrest OPC differentiation at a late progenitor stage and miR-145-5p at a premyelinating stage, whereas miR-214-3p promotes the differentiation of CG-4 cells. We propose several potential mRNA targets and hypothetical mechanisms by which each microRNA exerts its effect. We hereby open new perspectives in the research on OPC differentiation and the pathophysiology of demyelination/remyelination, and possibly even in the search for new remyelinating therapeutic strategies in the scope of MS.
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Affiliation(s)
- Océane Perdaens
- Neurochemistry Group, Institute of NeuroScience, Université catholique de Louvain (UCLouvain), Brussels, Belgium
| | - Pauline Bottemanne
- Bioanalysis and Pharmacology of Bioactive Lipids, Louvain Drug Research Institute, Université catholique de Louvain (UCLouvain), Brussels, Belgium
| | - Vincent van Pesch
- Neurochemistry Group, Institute of NeuroScience, Université catholique de Louvain (UCLouvain), Brussels, Belgium
- Department of Neurology, Cliniques universitaires Saint-Luc, Université catholique de Louvain (UCLouvain), Brussels, Belgium
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3
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Wang H, Zhou Y, Chu C, Xiao J, Zheng S, Korpal M, Korn JM, Penaloza T, Drake RR, Gan W, Gao X. Generating a Murine PTEN Null Cell Line to Discover the Key Role of p110β-PAK1 in Castration-Resistant Prostate Cancer Invasion. Mol Cancer Res 2023; 21:1317-1328. [PMID: 37606694 PMCID: PMC10841189 DOI: 10.1158/1541-7786.mcr-22-0808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 06/22/2023] [Accepted: 08/18/2023] [Indexed: 08/23/2023]
Abstract
Although androgen deprivation treatment often effectively decreases prostate cancer, incurable metastatic castration-resistant prostate cancer (CRPC) eventually occurs. It is important to understand how CRPC metastasis progresses, which is not clearly defined. The loss of PTEN, a phosphatase to dephosphorylate phosphatidylinositol 3,4,5-trisphosphate in the PI3K pathway, occurs in up to 70% to 80% of CRPC. We generated a mouse androgen-independent prostate cancer cell line (PKO) from PTEN null and Hi-Myc transgenic mice in C57BL/6 background. We confirmed that this PKO cell line has an activated PI3K pathway and can metastasize into the femur and tibia of immunodeficient nude and immunocompetent C57BL/6 mice. In vitro, we found that androgen deprivation significantly enhanced PKO cell migration/invasion via the p110β isoform-depended PAK1-MAPK activation. Inhibition of the p110β-PAK1 axis significantly decreased prostate cancer cell migration/invasion. Of note, our analysis using clinical samples showed that PAK1 is more activated in CRPC than in advanced prostate cancer; high PAK1/phosphorylated-PAK1 levels are associated with decreased survival rates in patients with CRPC. All the information suggests that this cell line reflects the characteristics of CRPC cells and can be applied to dissect the mechanism of CRPC initiation and progression. This study also shows that PAK1 is a potential target for CRPC treatment. IMPLICATIONS This study uses a newly generated PTEN null prostate cancer cell line to define a critical functional role of p110β-PAK1 in CRPC migration/invasion. This study also shows that the p110β-PAK1 axis can potentially be a therapeutic target in CRPC metastasis.
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Affiliation(s)
- Haizhen Wang
- Department of Cell and Molecular Pharmacology & Experimental Therapeutics, Medical University of South Carolina, Charleston, South Carolina, USA
- Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Yu Zhou
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Center for Medical Genetics, Sichuan Academy of Medical Sciences, Sichuan Provincial People’s Hospital, University of Electronic Science and Technology, Chengdu, Sichuan, China
| | - Chen Chu
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Jialing Xiao
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Center for Medical Genetics, Sichuan Academy of Medical Sciences, Sichuan Provincial People’s Hospital, University of Electronic Science and Technology, Chengdu, Sichuan, China
| | - Shanshan Zheng
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Manav Korpal
- Oncology Disease Area, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts, USA
| | - Joshua M Korn
- Oncology Disease Area, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts, USA
| | - Tiffany Penaloza
- Department of Cell and Molecular Pharmacology & Experimental Therapeutics, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Richard R. Drake
- Department of Cell and Molecular Pharmacology & Experimental Therapeutics, Medical University of South Carolina, Charleston, South Carolina, USA
- Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Wenjian Gan
- Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina, USA
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Xueliang Gao
- Department of Cell and Molecular Pharmacology & Experimental Therapeutics, Medical University of South Carolina, Charleston, South Carolina, USA
- Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina, USA
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4
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Reinhardt R, Leonard TA. A critical evaluation of protein kinase regulation by activation loop autophosphorylation. eLife 2023; 12:e88210. [PMID: 37470698 PMCID: PMC10359097 DOI: 10.7554/elife.88210] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 07/07/2023] [Indexed: 07/21/2023] Open
Abstract
Phosphorylation of proteins is a ubiquitous mechanism of regulating their function, localization, or activity. Protein kinases, enzymes that use ATP to phosphorylate protein substrates are, therefore, powerful signal transducers in eukaryotic cells. The mechanism of phosphoryl-transfer is universally conserved among protein kinases, which necessitates the tight regulation of kinase activity for the orchestration of cellular processes with high spatial and temporal fidelity. In response to a stimulus, many kinases enhance their own activity by autophosphorylating a conserved amino acid in their activation loop, but precisely how this reaction is performed is controversial. Classically, kinases that autophosphorylate their activation loop are thought to perform the reaction in trans, mediated by transient dimerization of their kinase domains. However, motivated by the recently discovered regulation mechanism of activation loop cis-autophosphorylation by a kinase that is autoinhibited in trans, we here review the various mechanisms of autoregulation that have been proposed. We provide a framework for critically evaluating biochemical, kinetic, and structural evidence for protein kinase dimerization and autophosphorylation, and share some thoughts on the implications of these mechanisms within physiological signaling networks.
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Affiliation(s)
- Ronja Reinhardt
- Max Perutz Labs, Vienna Biocenter Campus (VBC)ViennaAustria
- Medical University of Vienna, Center for Medical BiochemistryViennaAustria
| | - Thomas A Leonard
- Max Perutz Labs, Vienna Biocenter Campus (VBC)ViennaAustria
- Medical University of Vienna, Center for Medical BiochemistryViennaAustria
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5
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Dobrigna M, Poëa-Guyon S, Rousseau V, Vincent A, Toutain A, Barnier JV. The molecular basis of p21-activated kinase-associated neurodevelopmental disorders: From genotype to phenotype. Front Neurosci 2023; 17:1123784. [PMID: 36937657 PMCID: PMC10017488 DOI: 10.3389/fnins.2023.1123784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 02/13/2023] [Indexed: 03/06/2023] Open
Abstract
Although the identification of numerous genes involved in neurodevelopmental disorders (NDDs) has reshaped our understanding of their etiology, there are still major obstacles in the way of developing therapeutic solutions for intellectual disability (ID) and other NDDs. These include extensive clinical and genetic heterogeneity, rarity of recurrent pathogenic variants, and comorbidity with other psychiatric traits. Moreover, a large intragenic mutational landscape is at play in some NDDs, leading to a broad range of clinical symptoms. Such diversity of symptoms is due to the different effects DNA variations have on protein functions and their impacts on downstream biological processes. The type of functional alterations, such as loss or gain of function, and interference with signaling pathways, has yet to be correlated with clinical symptoms for most genes. This review aims at discussing our current understanding of how the molecular changes of group I p21-activated kinases (PAK1, 2 and 3), which are essential actors of brain development and function; contribute to a broad clinical spectrum of NDDs. Identifying differences in PAK structure, regulation and spatio-temporal expression may help understanding the specific functions of each group I PAK. Deciphering how each variation type affects these parameters will help uncover the mechanisms underlying mutation pathogenicity. This is a prerequisite for the development of personalized therapeutic approaches.
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Affiliation(s)
- Manon Dobrigna
- Institut des Neurosciences Paris-Saclay, UMR 9197, CNRS, Université Paris-Saclay, Saclay, France
| | - Sandrine Poëa-Guyon
- Institut des Neurosciences Paris-Saclay, UMR 9197, CNRS, Université Paris-Saclay, Saclay, France
| | - Véronique Rousseau
- Institut des Neurosciences Paris-Saclay, UMR 9197, CNRS, Université Paris-Saclay, Saclay, France
| | - Aline Vincent
- Department of Genetics, EA7450 BioTARGen, University Hospital of Caen, Caen, France
| | - Annick Toutain
- Department of Genetics, University Hospital of Tours, UMR 1253, iBrain, Université de Tours, INSERM, Tours, France
| | - Jean-Vianney Barnier
- Institut des Neurosciences Paris-Saclay, UMR 9197, CNRS, Université Paris-Saclay, Saclay, France
- *Correspondence: Jean-Vianney Barnier,
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6
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Chetty AK, Ha BH, Boggon TJ. Rho family GTPase signaling through type II p21-activated kinases. Cell Mol Life Sci 2022; 79:598. [PMID: 36401658 PMCID: PMC10105373 DOI: 10.1007/s00018-022-04618-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 10/07/2022] [Accepted: 10/28/2022] [Indexed: 11/21/2022]
Abstract
Signaling from the Rho family small GTPases controls a wide range of signaling outcomes. Key among the downstream effectors for many of the Rho GTPases are the p21-activated kinases, or PAK group. The PAK family comprises two types, the type I PAKs (PAK1, 2 and 3) and the type II PAKs (PAK4, 5 and 6), which have distinct structures and mechanisms of regulation. In this review, we discuss signal transduction from Rho GTPases with a focus on the type II PAKs. We discuss the role of PAKs in signal transduction pathways and selectivity of Rho GTPases for PAK family members. We consider the less well studied of the Rho GTPases and their PAK-related signaling. We then discuss the molecular basis for kinase domain recognition of substrates and for regulation of signaling. We conclude with a discussion of the role of PAKs in cross talk between Rho family small GTPases and the roles of PAKs in disease.
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Affiliation(s)
- Ashwin K Chetty
- Yale College, New Haven, CT, 06520, USA
- Department of Molecular Biophysics and Biochemistry, Yale University, 333 Cedar Street, New Haven, CT, 06520, USA
| | - Byung Hak Ha
- Department of Pharmacology, Yale University, 333 Cedar Street, New Haven, CT, 06520, USA
| | - Titus J Boggon
- Department of Molecular Biophysics and Biochemistry, Yale University, 333 Cedar Street, New Haven, CT, 06520, USA.
- Department of Pharmacology, Yale University, 333 Cedar Street, New Haven, CT, 06520, USA.
- Yale Cancer Center, Yale University, 333 Cedar Street, New Haven, CT, 06520, USA.
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7
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McGarry DJ, Castino G, Lilla S, Carnet A, Kelly L, Micovic K, Zanivan S, Olson MF. MICAL1 activation by PAK1 mediates actin filament disassembly. Cell Rep 2022; 41:111442. [PMID: 36198272 DOI: 10.1016/j.celrep.2022.111442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 06/14/2022] [Accepted: 09/09/2022] [Indexed: 11/03/2022] Open
Abstract
The MICAL1 monooxygenase is an important regulator of filamentous actin (F-actin) structures. Although MICAL1 has been shown to be regulated via protein-protein interactions at the autoinhibitory carboxyl terminus, a link between actin-regulatory RHO GTPase signaling pathways and MICAL1 has not been established. We show that the CDC42 GTPase effector PAK1 associates with and phosphorylates MICAL1 on two serine residues, leading to accelerated F-actin disassembly. PAK1 binds to the amino-terminal catalytic monooxygenase and calponin homology domains, distinct from the autoinhibitory carboxyl terminus. Extracellular ligand stimulation leads to PAK-dependent phosphorylation, linking external signals to MICAL1 phosphorylation. Mass spectrometry indicates that MICAL1 co-expression with CDC42 and PAK1 increases MICAL1 association with hundreds of proteins, including the previously described MICAL1-interacting proteins RAB10 and RAB7A. These results provide insights into a redox-mediated pathway linking extracellular signals to cytoskeleton regulation via a RHO GTPase and indicate a means of communication between RHO and RAB GTPases.
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Affiliation(s)
- David J McGarry
- Department of Chemistry and Biology, Toronto Metropolitan University, Toronto, ON M5B 2K3, Canada
| | - Giovanni Castino
- Department of Chemistry and Biology, Toronto Metropolitan University, Toronto, ON M5B 2K3, Canada
| | - Sergio Lilla
- Cancer Research UK Beatson Institute, Glasgow G61 1BD, UK
| | - Alexandre Carnet
- Department of Chemistry and Biology, Toronto Metropolitan University, Toronto, ON M5B 2K3, Canada
| | - Loughlin Kelly
- Department of Chemistry and Biology, Toronto Metropolitan University, Toronto, ON M5B 2K3, Canada
| | - Katarina Micovic
- Department of Chemistry and Biology, Toronto Metropolitan University, Toronto, ON M5B 2K3, Canada
| | - Sara Zanivan
- Cancer Research UK Beatson Institute, Glasgow G61 1BD, UK; Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Michael F Olson
- Department of Chemistry and Biology, Toronto Metropolitan University, Toronto, ON M5B 2K3, Canada.
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8
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La Serra MA, Vidossich P, Acquistapace I, Ganesan AK, De Vivo M. Alchemical Free Energy Calculations to Investigate Protein-Protein Interactions: the Case of the CDC42/PAK1 Complex. J Chem Inf Model 2022; 62:3023-3033. [PMID: 35679463 PMCID: PMC9241073 DOI: 10.1021/acs.jcim.2c00348] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
![]()
Here, we show that
alchemical free energy calculations can quantitatively
compute the effect of mutations at the protein–protein interface.
As a test case, we have used the protein complex formed by the small
Rho-GTPase CDC42 and its downstream effector PAK1, a serine/threonine
kinase. Notably, the CDC42/PAK1 complex offers a wealth of structural,
mutagenesis, and binding affinity data because of its central role
in cellular signaling and cancer progression. In this context, we
have considered 16 mutations in the CDC42/PAK1 complex and obtained
excellent agreement between computed and experimental data on binding
affinity. Importantly, we also show that a careful analysis of the
side-chain conformations in the mutated amino acids can considerably
improve the computed estimates, solving issues related to sampling
limitations. Overall, this study demonstrates that alchemical free
energy calculations can conveniently be integrated into the design
of experimental mutagenesis studies.
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Affiliation(s)
- Maria Antonietta La Serra
- Laboratory of Molecular Modeling and Drug Discovery, Istituto Italiano di Tecnologia, via Morego 30, Genoa 16163, Italy
| | - Pietro Vidossich
- Laboratory of Molecular Modeling and Drug Discovery, Istituto Italiano di Tecnologia, via Morego 30, Genoa 16163, Italy
| | - Isabella Acquistapace
- Laboratory of Molecular Modeling and Drug Discovery, Istituto Italiano di Tecnologia, via Morego 30, Genoa 16163, Italy
| | - Anand K Ganesan
- Department of Dermatology, University of California, Irvine, Irvine, California 92697, United States.,Department of Biological Chemistry, University of California, Irvine, Irvine, California 92697, United States
| | - Marco De Vivo
- Laboratory of Molecular Modeling and Drug Discovery, Istituto Italiano di Tecnologia, via Morego 30, Genoa 16163, Italy
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9
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Yu X, Huang C, Liu J, Shi X, Li X. The significance of PAK4 in signaling and clinicopathology: A review. Open Life Sci 2022; 17:586-598. [PMID: 35800076 PMCID: PMC9210989 DOI: 10.1515/biol-2022-0064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 02/17/2022] [Accepted: 03/12/2022] [Indexed: 11/15/2022] Open
Abstract
P21-activated protein kinases (PAKs) are thought to be at the center of tumor signaling pathways. As a representative member of the group II PAK family, P21-activated protein kinase 4 (PAK4) plays an important role in the development of tumors, with several biological functions such as participating in oncogenic transformation, promoting cell division, resisting aging and apoptosis, regulating cytoskeleton and adhesion, as well as suppressing antitumor immune responses. PAK4 is also crucial in biological processes, including the occurrence, proliferation, survival, migration, invasion, drug resistance, and immune escape of tumor cells. It is closely related to poor prognosis and tumor-related pathological indicators, which have significant clinical and pathological significance. Therefore, this article offers a review of the structure, activation, and biological functions of PAK4 and its clinical and pathological importance. This overview should be of assistance for future research on PAK4 and tumors and provide new ideas for tumor treatment and prognostic evaluation of patients.
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Affiliation(s)
- Xinbo Yu
- The First Clinical College, China Medical University, Shenyang, Liaoning Province 110122, China
| | - Changwei Huang
- The First Clinical College, China Medical University, Shenyang, Liaoning Province 110122, China
| | - Jiyuan Liu
- The First Clinical College, China Medical University, Shenyang, Liaoning Province 110122, China
| | - Xinyu Shi
- The Second Clinical College, China Medical University, Shenyang, Liaoning Province 110122, China
| | - Xiaodong Li
- Department of Cell Biology, Key Laboratory of Cell Biology, National Health Commission of the PRC and Key Laboratory of Medical Cell Biology, Ministry of Education of the PRC, China Medical University, Shenyang, Liaoning Province 110122, China
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10
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STE20 phosphorylation of AMPK related kinases revealed by biochemical purifications combined with genetics. J Biol Chem 2022; 298:101928. [PMID: 35413284 PMCID: PMC9112000 DOI: 10.1016/j.jbc.2022.101928] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/30/2022] [Accepted: 04/01/2022] [Indexed: 11/22/2022] Open
Abstract
We have recently purified mammalian sterile 20 (STE20)–like kinase 3 (MST3) as a kinase for the multifunctional kinases, AMP-activated protein kinase–related kinases (ARKs). However, unresolved questions from this study, such as remaining phosphorylation activities following deletion of the Mst3 gene from human embryonic kidney cells and mice, led us to conclude that there were additional kinases for ARKs. Further purification recovered Ca2+/calmodulin-dependent protein kinase kinases 1 and 2 (CaMKK1 and 2), and a third round of purification revealed mitogen-activated protein kinase kinase kinase kinase 5 (MAP4K5) as potential kinases of ARKs. We then demonstrated that MST3 and MAP4K5, both belonging to the STE20-like kinase family, could phosphorylate all 14 ARKs both in vivo and in vitro. Further examination of all 28 STE20 kinases detected variable phosphorylation activity on AMP-activated protein kinase (AMPK) and the salt-inducible kinase 3 (SIK3). Taken together, our results have revealed novel relationships between STE20 kinases and ARKs, with potential physiological and pathological implications.
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11
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Byun JK, Lee S, Kang GW, Lee YR, Park SY, Song IS, Yun JW, Lee J, Choi YK, Park KG. Macropinocytosis is an alternative pathway of cysteine acquisition and mitigates sorafenib-induced ferroptosis in hepatocellular carcinoma. J Exp Clin Cancer Res 2022; 41:98. [PMID: 35287706 PMCID: PMC8919615 DOI: 10.1186/s13046-022-02296-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 02/19/2022] [Indexed: 12/13/2022] Open
Abstract
Background Macropinocytosis, an important nutrient-scavenging pathway in certain cancer cells, allows cells to compensate for intracellular amino acid deficiency under nutrient-poor conditions. Ferroptosis caused by cysteine depletion plays a pivotal role in sorafenib responses during hepatocellular carcinoma (HCC) therapy. However, it is not known whether macropinocytosis functions as an alternative pathway to acquire cysteine in sorafenib-treated HCC, and whether it subsequently mitigates sorafenib-induced ferroptosis. This study aimed to investigate whether sorafenib drives macropinocytosis induction, and how macropinocytosis confers ferroptosis resistance on HCC cells. Methods Macropinocytosis, both in HCC cells and HCC tissues, was evaluated by measuring TMR-dextran uptake or lysosomal degradation of DQ-BSA, and ferroptosis was evaluated via C11-BODIPY fluorescence and 4-HNE staining. Sorafenib-induced ferroptosis and macropinocytosis were validated in tumor tissues taken from HCC patients who underwent ultrasound-guided needle biopsy. Results Sorafenib increased macropinocytosis in human HCC specimens and xenografted HCC tissues. Sorafenib-induced mitochondrial dysfunction was responsible for activation of PI3K-RAC1-PAK1 signaling, and amplified macropinocytosis in HCC. Importantly, macropinocytosis prevented sorafenib-induced ferroptosis by replenishing intracellular cysteine that was depleted by sorafenib treatment; this rendered HCC cells resistant to sorafenib. Finally, inhibition of macropinocytosis by amiloride markedly enhanced the anti-tumor effect of sorafenib, and sensitized resistant tumors to sorafenib. Conclusion In summary, sorafenib induced macropinocytosis, which conferred drug resistance by mitigating sorafenib-induced ferroptosis. Thus, targeting macropinocytosis is a promising therapeutic strategy to facilitate ferroptosis-based therapy for HCC. Graphic Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13046-022-02296-3.
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Affiliation(s)
- Jun-Kyu Byun
- Research Institute of Aging and Metabolism, Kyungpook National University, Daegu, Korea.,Department of Internal Medicine, School of Medicine, Kyungpook National University, Kyungpook National University Hospital, Daegu, Korea
| | - Seunghyeong Lee
- Department of Biomedical Science, Graduate School, Kyungpook National University, Daegu, Korea.,BK21 FOUR KNU Convergence Educational Program of Biomedical Sciences for Creative Future Talents, School of Medicine, Kyungpook National University, Daegu, Korea
| | - Gil Won Kang
- Department of Biomedical Science, Graduate School, Kyungpook National University, Daegu, Korea
| | - Yu Rim Lee
- Department of Internal Medicine, School of Medicine, Kyungpook National University, Kyungpook National University Hospital, Daegu, Korea
| | - Soo Young Park
- Department of Internal Medicine, School of Medicine, Kyungpook National University, Kyungpook National University Hospital, Daegu, Korea
| | - Im-Sook Song
- Research Institute of Pharmaceutical Science, College of Pharmacy, Kyungpook National University, Daegu, Korea
| | - Jae Won Yun
- Veterans Medical Research Institute, Veterans Health Service Medical Center, Seoul, Korea
| | - Jaebon Lee
- Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Yeon-Kyung Choi
- Research Institute of Aging and Metabolism, Kyungpook National University, Daegu, Korea. .,Department of Internal Medicine, School of Medicine, Kyungpook National University, Kyungpook National University Hospital, Daegu, Korea.
| | - Keun-Gyu Park
- Research Institute of Aging and Metabolism, Kyungpook National University, Daegu, Korea. .,Department of Internal Medicine, School of Medicine, Kyungpook National University, Kyungpook National University Hospital, Daegu, Korea. .,Department of Biomedical Science, Graduate School, Kyungpook National University, Daegu, Korea.
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12
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Scala M, Nishikawa M, Nagata KI, Striano P. Pathophysiological Mechanisms in Neurodevelopmental Disorders Caused by Rac GTPases Dysregulation: What's behind Neuro-RACopathies. Cells 2021; 10:3395. [PMID: 34943902 PMCID: PMC8699292 DOI: 10.3390/cells10123395] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 11/23/2021] [Accepted: 11/30/2021] [Indexed: 02/07/2023] Open
Abstract
Rho family guanosine triphosphatases (GTPases) regulate cellular signaling and cytoskeletal dynamics, playing a pivotal role in cell adhesion, migration, and cell cycle progression. The Rac subfamily of Rho GTPases consists of three highly homologous proteins, Rac 1-3. The proper function of Rac1 and Rac3, and their correct interaction with guanine nucleotide-exchange factors (GEFs) and GTPase-activating proteins (GAPs) are crucial for neural development. Pathogenic variants affecting these delicate biological processes are implicated in different medical conditions in humans, primarily neurodevelopmental disorders (NDDs). In addition to a direct deleterious effect produced by genetic variants in the RAC genes, a dysregulated GTPase activity resulting from an abnormal function of GEFs and GAPs has been involved in the pathogenesis of distinctive emerging conditions. In this study, we reviewed the current pertinent literature on Rac-related disorders with a primary neurological involvement, providing an overview of the current knowledge on the pathophysiological mechanisms involved in the neuro-RACopathies.
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Affiliation(s)
- Marcello Scala
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, 16132 Genoa, Italy;
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto Giannina Gaslini, 16147 Genoa, Italy
| | - Masashi Nishikawa
- Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Developmental Disability Center, 713-8 Kamiya, Kasugai 480-0392, Japan; (M.N.); (K.-i.N.)
| | - Koh-ichi Nagata
- Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Developmental Disability Center, 713-8 Kamiya, Kasugai 480-0392, Japan; (M.N.); (K.-i.N.)
- Department of Neurochemistry, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Nagoya 466-8550, Japan
| | - Pasquale Striano
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, 16132 Genoa, Italy;
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto Giannina Gaslini, 16147 Genoa, Italy
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13
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Magne N, Rousseau V, Duarte K, Poëa-Guyon S, Gleize V, Mutel A, Schmitt C, Castel H, Idbaih A, Huillard E, Sanson M, Barnier JV. PAK3 is a key signature gene of the glioma proneural subtype and affects its proliferation, differentiation and growth. Cell Oncol (Dordr) 2021; 44:1257-1271. [PMID: 34550532 DOI: 10.1007/s13402-021-00635-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/01/2021] [Indexed: 02/06/2023] Open
Abstract
PURPOSE Gliomas are the most lethal adult primary brain cancers. Recent advances in their molecular characterization have contributed to a better understanding of their pathophysiology, but there is still a need to identify key genes controling glioma cell proliferation and differentiation. The p21-activated kinases PAK1 and PAK2 play essential roles in cell division and brain development and are well-known oncogenes. In contrast, the role of PAK3 in cancer is poorly understood. It is known, however, that this gene is involved in brain ontogenesis and has been identified as a gene of the proneural subtype signature in glioblastomas. METHODS To better understand the role of PAK kinases in the pathophysiology of gliomas, we conducted expression analyses by querying multiple gene expression databases and analyzing primary human glioma samples. We next studied PAK3 expression upon differentiation in patient-derived cell lines (PDCLs) and the effects of PAK3 inhibition by lentiviral-mediated shRNA on glioma cell proliferation, differentiation and tumor growth. RESULTS We show that contrary to PAK1 and PAK2, high PAK3 expression positively correlates with a longer survival of glioma patients. We also found that PAK3 displays differential expression patterns between glioma sub-groups with a higher expression in 1p/19q-codeleted oligodendrogliomas, and is highly expressed in tumors and PDCLs of the proneural subtype. In PDCLs, high PAK3 expression negatively correlated with proliferation and positively correlated with neuronal differentiation. Inhibition of PAK3 expression increased PDCL proliferation and glioma tumor growth in nude mice. CONCLUSIONS Our results indicate that PAK3 plays a unique role among PAKs in glioma development and may represent a potential therapeutic target.
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Affiliation(s)
- Nathalie Magne
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris-Saclay, 91190, Gif-sur-Yvette, France
| | - Véronique Rousseau
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris-Saclay, 91190, Gif-sur-Yvette, France
| | - Kévin Duarte
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris-Saclay, 91190, Gif-sur-Yvette, France
| | - Sandrine Poëa-Guyon
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris-Saclay, 91190, Gif-sur-Yvette, France
| | - Vincent Gleize
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau, ICM, AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Service de Neurologie 2-Mazarin, 75013, Paris, France
| | - Alexandre Mutel
- Normandie Univ, UNIROUEN, INSERM, U1239, Laboratoire Différenciation Et Communication Neuronale Et Neuroendocrine, Institut de Recherche Et D'Innovation Biomédicale de Normandie, 76000, Rouen, France
| | - Charlotte Schmitt
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau, ICM, AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Service de Neurologie 2-Mazarin, 75013, Paris, France
| | - Hélène Castel
- Normandie Univ, UNIROUEN, INSERM, U1239, Laboratoire Différenciation Et Communication Neuronale Et Neuroendocrine, Institut de Recherche Et D'Innovation Biomédicale de Normandie, 76000, Rouen, France
| | - Ahmed Idbaih
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau, ICM, AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Service de Neurologie 2-Mazarin, 75013, Paris, France
| | - Emmanuelle Huillard
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau, ICM, AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Service de Neurologie 2-Mazarin, 75013, Paris, France
| | - Marc Sanson
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau, ICM, AP-HP, Hôpitaux Universitaires La Pitié Salpêtrière - Charles Foix, Service de Neurologie 2-Mazarin, 75013, Paris, France
| | - Jean-Vianney Barnier
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris-Saclay, 91190, Gif-sur-Yvette, France.
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14
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Wang Y, Guo F. Group I PAKs in myelin formation and repair of the central nervous system: what, when, and how. Biol Rev Camb Philos Soc 2021; 97:615-639. [PMID: 34811887 DOI: 10.1111/brv.12815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 10/20/2021] [Accepted: 11/04/2021] [Indexed: 11/30/2022]
Abstract
p21-activated kinases (PAKs) are a family of cell division control protein 42/ras-related C3 botulinum toxin substrate 1 (Cdc42/Rac1)-activated serine/threonine kinases. Group I PAKs (PAK1-3) have distinct activation mechanisms from group II PAKs (PAK4-6) and are the focus of this review. In transformed cancer cells, PAKs regulate a variety of cellular processes and molecular pathways which are also important for myelin formation and repair in the central nervous system (CNS). De novo mutations in group I PAKs are frequently seen in children with neurodevelopmental defects and white matter anomalies. Group I PAKs regulate virtually every aspect of neuronal development and function. Yet their functions in CNS myelination and remyelination remain incompletely defined. Herein, we highlight the current understanding of PAKs in regulating cellular and molecular pathways and discuss the status of PAK-regulated pathways in oligodendrocyte development. We point out outstanding questions and future directions in the research field of group I PAKs and oligodendrocyte development.
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Affiliation(s)
- Yan Wang
- Department of Neurology, Shriners Hospitals for Children/School of Medicine, Institute for Pediatric Regenerative Medicine (IPRM), University of California, Davis, 2425 Stockton Blvd, Sacramento, CA, 95817, U.S.A
| | - Fuzheng Guo
- Department of Neurology, Shriners Hospitals for Children/School of Medicine, Institute for Pediatric Regenerative Medicine (IPRM), University of California, Davis, 2425 Stockton Blvd, Sacramento, CA, 95817, U.S.A
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15
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Regulation of Rac1 Activation in Choroidal Endothelial Cells: Insights into Mechanisms in Age-Related Macular Degeneration. Cells 2021; 10:cells10092414. [PMID: 34572063 PMCID: PMC8469925 DOI: 10.3390/cells10092414] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 09/07/2021] [Accepted: 09/08/2021] [Indexed: 12/11/2022] Open
Abstract
Age-related macular degeneration (AMD) is one of the leading causes of blindness worldwide. Vision loss from the neovascular form is associated with the invasion of choroidal endothelial cells into the neural retina to form vision-threatening macular neovascularization (MNV). Anti-angiogenic agents are the current standard of care but are effective in only ~50% of AMD cases. The molecular mechanisms involved in invasive MNV point to the importance of regulating signaling pathways that lead to pathologic biologic outcomes. In studies testing the effects of AMD-related stresses, activation of the Rho GTPase, Rac1, was found to be important for the choroidal endothelial cell invasion into the neural retina. However, current approaches to prevent Rac1 activation are inefficient and less effective. We summarize active Rac1-mediated mechanisms that regulate choroidal endothelial cell migration. Specifically, we discuss our work regarding the role of a multidomain protein, IQ motif containing GTPase activating protein 1 (IQGAP1), in sustaining pathologic Rac1 activation and a mechanism by which active Rap1, a Ras-like GTPase, may prevent active Rac1-mediated choroidal endothelial cell migration.
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16
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Liaci C, Camera M, Caslini G, Rando S, Contino S, Romano V, Merlo GR. Neuronal Cytoskeleton in Intellectual Disability: From Systems Biology and Modeling to Therapeutic Opportunities. Int J Mol Sci 2021; 22:ijms22116167. [PMID: 34200511 PMCID: PMC8201358 DOI: 10.3390/ijms22116167] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 05/25/2021] [Accepted: 06/04/2021] [Indexed: 02/06/2023] Open
Abstract
Intellectual disability (ID) is a pathological condition characterized by limited intellectual functioning and adaptive behaviors. It affects 1–3% of the worldwide population, and no pharmacological therapies are currently available. More than 1000 genes have been found mutated in ID patients pointing out that, despite the common phenotype, the genetic bases are highly heterogeneous and apparently unrelated. Bibliomic analysis reveals that ID genes converge onto a few biological modules, including cytoskeleton dynamics, whose regulation depends on Rho GTPases transduction. Genetic variants exert their effects at different levels in a hierarchical arrangement, starting from the molecular level and moving toward higher levels of organization, i.e., cell compartment and functions, circuits, cognition, and behavior. Thus, cytoskeleton alterations that have an impact on cell processes such as neuronal migration, neuritogenesis, and synaptic plasticity rebound on the overall establishment of an effective network and consequently on the cognitive phenotype. Systems biology (SB) approaches are more focused on the overall interconnected network rather than on individual genes, thus encouraging the design of therapies that aim to correct common dysregulated biological processes. This review summarizes current knowledge about cytoskeleton control in neurons and its relevance for the ID pathogenesis, exploiting in silico modeling and translating the implications of those findings into biomedical research.
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Affiliation(s)
- Carla Liaci
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, 10126 Torino, Italy; (C.L.); (M.C.); (G.C.); (S.R.)
| | - Mattia Camera
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, 10126 Torino, Italy; (C.L.); (M.C.); (G.C.); (S.R.)
| | - Giovanni Caslini
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, 10126 Torino, Italy; (C.L.); (M.C.); (G.C.); (S.R.)
| | - Simona Rando
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, 10126 Torino, Italy; (C.L.); (M.C.); (G.C.); (S.R.)
| | - Salvatore Contino
- Department of Engineering, University of Palermo, Viale delle Scienze Ed. 8, 90128 Palermo, Italy;
| | - Valentino Romano
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Viale delle Scienze Ed. 16, 90128 Palermo, Italy;
| | - Giorgio R. Merlo
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, 10126 Torino, Italy; (C.L.); (M.C.); (G.C.); (S.R.)
- Correspondence: ; Tel.: +39-0116706449; Fax: +39-0116706432
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17
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Hawley E, Gehlhausen J, Karchugina S, Chow HY, Araiza-Olivera D, Radu M, Smith A, Burks C, Jiang L, Li X, Bessler W, Masters A, Edwards D, Burgin C, Jones D, Yates C, Clapp DW, Chernoff J, Park SJ. PAK1 inhibition reduces tumor size and extends the lifespan of mice in a genetically engineered mouse model of Neurofibromatosis Type 2 (NF2). Hum Mol Genet 2021; 30:1607-1617. [PMID: 34075397 DOI: 10.1093/hmg/ddab106] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 04/07/2021] [Accepted: 04/08/2021] [Indexed: 02/06/2023] Open
Abstract
Neurofibromatosis Type II (NF2) is an autosomal dominant cancer predisposition syndrome in which germline haploinsufficiency at the NF2 gene confers a greatly increased propensity for tumor development arising from tissues of neural crest derived origin. NF2 encodes the tumor suppressor, Merlin, and its biochemical function is incompletely understood. One well established function of Merlin is as a negative regulator of group A serine/threonine p21 activated kinases (PAKs). In these studies we explore the role of PAK1 and its closely related paralog, PAK2, both pharmacologically and genetically, in Merlin deficient Schwann cells and in a genetically engineered mouse model (GEMM) that develops spontaneous vestibular and spinal schwannomas. We demonstrate that PAK1 and PAK2 are both hyper activated in Merlin deficient murine schwannomas. In preclinical trials, a pan Group A PAK inhibitor, FRAX-1036, transiently reduced PAK1 and PAK2 phosphorylation in vitro, but had insignificant efficacy in vivo. NVS-PAK1-1, a PAK1 selective inhibitor, had a greater but still minimal effect on our GEMM phenotype. However, genetic ablation of Pak1 but not Pak2 reduced tumor formation in our NF2 GEMM. Moreover, germline genetic deletion of Pak1 was well tolerated while conditional deletion of Pak2 in Schwann cells resulted in significant morbidity and mortality. These data support the further development of PAK1-specific small molecule inhibitors and the therapeutic targeting of PAK1 in vestibular schwannomas and argue against PAK1 and PAK2 existing as functionally redundant protein isoforms in Schwann cells.
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Affiliation(s)
- Eric Hawley
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Jeffrey Gehlhausen
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Sofiia Karchugina
- Cancer Biology Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Hoi-Yee Chow
- Cancer Biology Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | | | - Maria Radu
- Cancer Biology Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Abbi Smith
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana
| | - Ciersten Burks
- Department of Otolaryngology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Li Jiang
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana
| | - Xiaohong Li
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana
| | - Waylan Bessler
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana
| | - Andrea Masters
- Clinical Pharmacology Analytical Core, Indiana University School of Medicine, Indianapolis, Indiana
| | - Donna Edwards
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Callie Burgin
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana
| | - David Jones
- Clinical Pharmacology Analytical Core, Indiana University School of Medicine, Indianapolis, Indiana
| | - Charles Yates
- Department of Otolaryngology, Indiana University School of Medicine, Indianapolis, Indiana
| | - D Wade Clapp
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana.,Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana
| | - Jonathan Chernoff
- Cancer Biology Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Su-Jung Park
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana
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18
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Derivation of stationary distributions of biochemical reaction networks via structure transformation. Commun Biol 2021; 4:620. [PMID: 34031517 PMCID: PMC8144570 DOI: 10.1038/s42003-021-02117-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 04/16/2021] [Indexed: 02/04/2023] Open
Abstract
Long-term behaviors of biochemical reaction networks (BRNs) are described by steady states in deterministic models and stationary distributions in stochastic models. Unlike deterministic steady states, stationary distributions capturing inherent fluctuations of reactions are extremely difficult to derive analytically due to the curse of dimensionality. Here, we develop a method to derive analytic stationary distributions from deterministic steady states by transforming BRNs to have a special dynamic property, called complex balancing. Specifically, we merge nodes and edges of BRNs to match in- and out-flows of each node. This allows us to derive the stationary distributions of a large class of BRNs, including autophosphorylation networks of EGFR, PAK1, and Aurora B kinase and a genetic toggle switch. This reveals the unique properties of their stochastic dynamics such as robustness, sensitivity, and multi-modality. Importantly, we provide a user-friendly computational package, CASTANET, that automatically derives symbolic expressions of the stationary distributions of BRNs to understand their long-term stochasticity.
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19
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Zhang K, Wang Y, Fan T, Zeng C, Sun ZS. The p21-activated kinases in neural cytoskeletal remodeling and related neurological disorders. Protein Cell 2020; 13:6-25. [PMID: 33306168 PMCID: PMC8776968 DOI: 10.1007/s13238-020-00812-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 11/19/2020] [Indexed: 12/15/2022] Open
Abstract
The serine/threonine p21-activated kinases (PAKs), as main effectors of the Rho GTPases Cdc42 and Rac, represent a group of important molecular switches linking the complex cytoskeletal networks to broad neural activity. PAKs show wide expression in the brain, but they differ in specific cell types, brain regions, and developmental stages. PAKs play an essential and differential role in controlling neural cytoskeletal remodeling and are related to the development and fate of neurons as well as the structural and functional plasticity of dendritic spines. PAK-mediated actin signaling and interacting functional networks represent a common pathway frequently affected in multiple neurodevelopmental and neurodegenerative disorders. Considering specific small-molecule agonists and inhibitors for PAKs have been developed in cancer treatment, comprehensive knowledge about the role of PAKs in neural cytoskeletal remodeling will promote our understanding of the complex mechanisms underlying neurological diseases, which may also represent potential therapeutic targets of these diseases.
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Affiliation(s)
- Kaifan Zhang
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, 100101, China.,Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, 325000, China
| | - Yan Wang
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Tianda Fan
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, 325000, China
| | - Cheng Zeng
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, 100101, China.,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhong Sheng Sun
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, 100101, China. .,Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, 325000, China. .,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, 100049, China. .,State Key Laboratory of Integrated Management of Pest Insects and Rodents, Chinese Academy of Sciences, Beijing, 100101, China.
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20
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Yao D, Li C, Rajoka MSR, He Z, Huang J, Wang J, Zhang J. P21-Activated Kinase 1: Emerging biological functions and potential therapeutic targets in Cancer. Am J Cancer Res 2020; 10:9741-9766. [PMID: 32863957 PMCID: PMC7449905 DOI: 10.7150/thno.46913] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 07/23/2020] [Indexed: 02/06/2023] Open
Abstract
The p21-Activated kinase 1 (PAK1), a member of serine-threonine kinases family, was initially identified as an interactor of the Rho GTPases RAC1 and CDC42, which affect a wide range of processes associated with cell motility, survival, metabolism, cell cycle, proliferation, transformation, stress, inflammation, and gene expression. Recently, the PAK1 has emerged as a potential therapeutic target in cancer due to its role in many oncogenic signaling pathways. Many PAK1 inhibitors have been developed as potential preclinical agents for cancer therapy. Here, we provide an overview of essential roles that PAK1 plays in cancer, including its structure and autoactivation mechanism, its crucial function from onset to progression to metastasis, metabolism, immune escape and even drug resistance in cancer; endogenous regulators; and cancer-related pathways. We also summarize the reported PAK1 small-molecule inhibitors based on their structure types and their potential application in cancer. In addition, we provide overviews on current progress and future challenges of PAK1 in cancer, hoping to provide new ideas for the diagnosis and treatment of cancer.
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21
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Horn S, Au M, Basel-Salmon L, Bayrak-Toydemir P, Chapin A, Cohen L, Elting MW, Graham JM, Gonzaga-Jauregui C, Konen O, Holzer M, Lemke J, Miller CE, Rey LK, Wolf NI, Weiss MM, Waisfisz Q, Mirzaa GM, Wieczorek D, Sticht H, Abou Jamra R. De novo variants in PAK1 lead to intellectual disability with macrocephaly and seizures. Brain 2020; 142:3351-3359. [PMID: 31504246 PMCID: PMC6821231 DOI: 10.1093/brain/awz264] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 06/07/2019] [Accepted: 07/04/2019] [Indexed: 12/14/2022] Open
Abstract
Using trio exome sequencing, we identified de novo heterozygous missense variants in PAK1 in four unrelated individuals with intellectual disability, macrocephaly and seizures. PAK1 encodes the p21-activated kinase, a major driver of neuronal development in humans and other organisms. In normal neurons, PAK1 dimers reside in a trans-inhibited conformation, where each autoinhibitory domain covers the kinase domain of the other monomer. Upon GTPase binding via CDC42 or RAC1, the PAK1 dimers dissociate and become activated. All identified variants are located within or close to the autoinhibitory switch domain that is necessary for trans-inhibition of resting PAK1 dimers. Protein modelling supports a model of reduced ability of regular autoinhibition, suggesting a gain of function mechanism for the identified missense variants. Alleviated dissociation into monomers, autophosphorylation and activation of PAK1 influences the actin dynamics of neurite outgrowth. Based on our clinical and genetic data, as well as the role of PAK1 in brain development, we suggest that gain of function pathogenic de novo missense variants in PAK1 lead to moderate-to-severe intellectual disability, macrocephaly caused by the presence of megalencephaly and ventriculomegaly, (febrile) seizures and autism-like behaviour.
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Affiliation(s)
- Susanne Horn
- Institute of Human Genetics, University Medical Center Leipzig, Leipzig, Germany
| | - Margaret Au
- Department of Pediatrics, Cedars Sinai Medical Center, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Lina Basel-Salmon
- Raphael Recanati Genetic Institute, Rabin Medical Center-Beilinson Hospital, Petach Tikva, Israel.,Pediatric Genetics Clinic, Schneider Children's Medical Center of Israel, Petach Tikva, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Felsenstein Medical Research Center, Rabin Medical Center, Petach Tikva, Israel
| | - Pinar Bayrak-Toydemir
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT, USA; ARUP Laboratories, Salt Lake City, UT, USA
| | | | - Lior Cohen
- Raphael Recanati Genetic Institute, Rabin Medical Center-Beilinson Hospital, Petach Tikva, Israel.,Pediatric Genetics Clinic, Schneider Children's Medical Center of Israel, Petach Tikva, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Felsenstein Medical Research Center, Rabin Medical Center, Petach Tikva, Israel
| | - Mariet W Elting
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Clinical Genetics, De Boelelaan 1117, Amsterdam, The Netherlands
| | - John M Graham
- Department of Pediatrics, Cedars Sinai Medical Center, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | | | - Osnat Konen
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Department of Pediatric Radiology, Schneider Children's Medical Center of Israel, Petach Tikva, Israel
| | - Max Holzer
- Department for Molecular and Cellular Mechanisms of Neurodegeneration, Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Johannes Lemke
- Institute of Human Genetics, University Medical Center Leipzig, Leipzig, Germany
| | | | - Linda K Rey
- Institute of Human Genetics, University Hospital Duesseldorf, Heinrich-Heine-University Duesseldorf, Duesseldorf, Germany
| | - Nicole I Wolf
- Department of Child Neurology, Emma Children's Hospital, Amsterdam UMC, Vrije Universiteit Amsterdam, and Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Marjan M Weiss
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Clinical Genetics, De Boelelaan 1117, Amsterdam, The Netherlands
| | - Quinten Waisfisz
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Clinical Genetics, De Boelelaan 1117, Amsterdam, The Netherlands
| | - Ghayda M Mirzaa
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington, USA.,Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - Dagmar Wieczorek
- Institute of Human Genetics, University Hospital Duesseldorf, Heinrich-Heine-University Duesseldorf, Duesseldorf, Germany
| | - Heinrich Sticht
- Institute of Biochemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Rami Abou Jamra
- Institute of Human Genetics, University Medical Center Leipzig, Leipzig, Germany
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22
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Chen KJ, Chiang TC, Yu CJ, Lee FJS. Cooperative recruitment of Arl4A and Pak1 to the plasma membrane contributes to sustained Pak1 activation for cell migration. J Cell Sci 2020; 133:jcs233361. [PMID: 31932503 DOI: 10.1242/jcs.233361] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 12/17/2019] [Indexed: 01/27/2023] Open
Abstract
Cell migration requires the coordination of multiple signaling pathways involved in membrane dynamics and cytoskeletal rearrangement. The Arf-like small GTPase Arl4A has been shown to modulate actin cytoskeleton remodeling. However, evidence of the function of Arl4A in cell migration is insufficient. Here, we report that Arl4A acts with the serine/threonine protein kinase Pak1 to modulate cell migration through their cooperative recruitment to the plasma membrane. We first observed that Arl4A and its isoform Arl4D interact with Pak1 and Pak2 and showed that Arl4A recruits Pak1 and Pak2 to the plasma membrane. The fibronectin-induced Pak1 localization at the plasma membrane is reduced in Arl4A-depleted cells. Unexpectedly, we found that Pak1, but not Arl4A-binding-defective Pak1, can recruit a cytoplasmic myristoylation-deficient Arl4A-G2A mutant to the plasma membrane. Furthermore, we found that the Arl4A-Pak1 interaction, which is independent of Rac1 binding to Pak1, is required for Arl4A-induced cell migration. Thus, we infer that there is feedback regulation between Arl4A and Pak1, in which they mutually recruit each other to the plasma membrane for Pak1 activation, thereby modulating cell migration through direct interaction.
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Affiliation(s)
- Kuan-Jung Chen
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei 10002, Taiwan
- Department of Medical Research, National Taiwan University Hospital, Taipei 10002, Taiwan
| | - Tsai-Chen Chiang
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei 10002, Taiwan
- Department of Medical Research, National Taiwan University Hospital, Taipei 10002, Taiwan
| | - Chia-Jung Yu
- Department of Cell and Molecular Biology, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
- Department of Thoracic Medicine, Chang Gung Memorial Hospital, Linkou, Taoyuan 33305, Taiwan
| | - Fang-Jen S Lee
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei 10002, Taiwan
- Department of Medical Research, National Taiwan University Hospital, Taipei 10002, Taiwan
- Center of Precision Medicine, College of Medicine, National Taiwan University, Taipei 10002, Taiwan
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A novel PAK1 variant causative of neurodevelopmental disorder with postnatal macrocephaly. J Hum Genet 2020; 65:481-485. [PMID: 32005903 DOI: 10.1038/s10038-020-0728-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 11/14/2019] [Accepted: 01/17/2020] [Indexed: 11/08/2022]
Abstract
p21-activated kinases (PAKs) are protein serine/threonine kinases stimulated by Rho-family p21 GTPases such as CDC42 and RAC. PAKs have been implicated in several human disorders, with pathogenic variants in PAK3 associated with intellectual disability and several PAK members, especially PAK1 and PAK4, overexpressed in human cancer. Recently, de novo PAK1 variants were reported to be causative of neurodevelopmental disorder (ND) with secondary macrocephaly in three patients. We herein report a fourth patient with ND, epilepsy, and macrocephaly caused by a de novo PAK1 missense variant. Two previously reported missense PAK1 variants functioned as activating alleles by reducing PAK1 homodimerization. To examine the pathogenicity of the identified novel p.Ser110Thr variant, we carried out in silico structural analysis. Our findings suggest that this variant also prevents PAK1 homodimerization, leading to constitutive PAK1 activation.
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24
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Ito H, Tsunoda T, Riku M, Inaguma S, Inoko A, Murakami H, Ikeda H, Matsuda M, Kasai K. Indispensable role of STIL in the regulation of cancer cell motility through the lamellipodial accumulation of ARHGEF7-PAK1 complex. Oncogene 2019; 39:1931-1943. [PMID: 31754215 DOI: 10.1038/s41388-019-1115-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 11/06/2019] [Accepted: 11/11/2019] [Indexed: 01/08/2023]
Abstract
Cell motility is a tightly regulated phenomenon that supports the accurate formation of organ structure during development and homeostasis, including wound healing and inflammation. Meanwhile, cancer cells exhibit dysregulated motility, which causes spreading and invasion. The Dbl family RhoGEF ARHGEF7/β-PIX and its binding partner p21-activated kinase PAK1 are overexpressed in a variety of cancers and have been shown to be responsible for cancer cell migration. A key step in motility is the intracellular transport of ARHGEF7-PAK1 complex to the migrating front of cells, where lamellipodia protrusion and cytoskeletal remodeling efficiently occur. However, the molecular mechanisms of the intracellular transport of this complex are not fully understood. Here we revealed that SCL/TAL1-interrupting locus (STIL) is indispensable for the efficient migration of cancer cells. STIL forms a ternary complex with ARHGEF7 and PAK1 and accumulates with those proteins at the lamellipodia protrusion of motile cells. Knockdown of STIL impedes the accumulation of ARHGEF7-PAK1 complex within membrane ruffles and attenuates the phosphorylation of PAK1 substrates and cortical actin remodeling at the migrating front. Intriguingly, ARHGEF7 knockdown also diminishes STIL and PAK1 accumulation in membrane ruffles. Either STIL or ARHGEF7 knockdown impedes cell migration and Rac1 activity at the migrating front of cells. These results indicate that STIL is involved in the ARHGEF7-mediated positive-feedback activation of cytoskeletal remodeling through accumulating the ARHGEF7-PAK1 complex in lamellipodia. We conclude that its involvement is crucial for the polarized formation of Rac1-mediated leading edge, which supports the efficient migration of cancer cells.
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Affiliation(s)
- Hideaki Ito
- Department of Pathology, Aichi Medical University School of Medicine, Nagakute, Japan
| | - Takumi Tsunoda
- Department of Pathology, Aichi Medical University School of Medicine, Nagakute, Japan
| | - Miho Riku
- Department of Pathology, Aichi Medical University School of Medicine, Nagakute, Japan
| | - Shingo Inaguma
- Department of Pathology, Aichi Medical University School of Medicine, Nagakute, Japan
| | - Akihito Inoko
- Department of Pathology, Aichi Medical University School of Medicine, Nagakute, Japan
| | - Hideki Murakami
- Department of Pathology, Aichi Medical University School of Medicine, Nagakute, Japan
| | - Hiroshi Ikeda
- Department of Pathology, Aichi Medical University School of Medicine, Nagakute, Japan
| | - Michiyuki Matsuda
- Department of Pathology and Biology of Diseases, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kenji Kasai
- Department of Pathology, Aichi Medical University School of Medicine, Nagakute, Japan.
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25
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Grebeňová D, Holoubek A, Röselová P, Obr A, Brodská B, Kuželová K. PAK1, PAK1Δ15, and PAK2: similarities, differences and mutual interactions. Sci Rep 2019; 9:17171. [PMID: 31748572 PMCID: PMC6868145 DOI: 10.1038/s41598-019-53665-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 09/30/2019] [Indexed: 12/16/2022] Open
Abstract
P21-activated kinases (PAK) are key effectors of the small GTPases Rac1 and Cdc42, as well as of Src family kinases. In particular, PAK1 has several well-documented roles, both kinase-dependent and kinase-independent, in cancer-related processes, such as cell proliferation, adhesion, and migration. However, PAK1 properties and functions have not been attributed to individual PAK1 isoforms: besides the full-length kinase (PAK1-full), a splicing variant lacking the exon 15 (PAK1Δ15) is annotated in protein databases. In addition, it is not clear if PAK1 and PAK2 are functionally overlapping. Using fluorescently tagged forms of human PAK1-full, PAK1Δ15, and PAK2, we analyzed their intracellular localization and mutual interactions. Effects of PAK inhibition (IPA-3, FRAX597) or depletion (siRNA) on cell-surface adhesion were monitored by real-time microimpedance measurement. Both PAK1Δ15 and PAK2, but not PAK1-full, were enriched in focal adhesions, indicating that the C-terminus might be important for PAK intracellular localization. Using coimmunoprecipitation, we documented direct interactions among the studied PAK group I members: PAK1 and PAK2 form homodimers, but all possible heterocomplexes were also detected. Interaction of PAK1Δ15 or PAK2 with PAK1-full was associated with extensive PAK1Δ15/PAK2 cleavage. The impedance measurements indicate, that PAK2 depletion slows down cell attachment to a surface, and that PAK1-full is involved in cell spreading. Altogether, our data suggest a complex interplay among different PAK group I members, which have non-redundant functions.
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Affiliation(s)
- Dana Grebeňová
- Department of Proteomics, Institute of Hematology and Blood Transfusion, U Nemocnice 1, 128 20, Prague, Czech Republic
| | - Aleš Holoubek
- Department of Proteomics, Institute of Hematology and Blood Transfusion, U Nemocnice 1, 128 20, Prague, Czech Republic
| | - Pavla Röselová
- Department of Proteomics, Institute of Hematology and Blood Transfusion, U Nemocnice 1, 128 20, Prague, Czech Republic
| | - Adam Obr
- Department of Proteomics, Institute of Hematology and Blood Transfusion, U Nemocnice 1, 128 20, Prague, Czech Republic
| | - Barbora Brodská
- Department of Proteomics, Institute of Hematology and Blood Transfusion, U Nemocnice 1, 128 20, Prague, Czech Republic
| | - Kateřina Kuželová
- Department of Proteomics, Institute of Hematology and Blood Transfusion, U Nemocnice 1, 128 20, Prague, Czech Republic.
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Zhang X, Fang J, Chen S, Wang W, Meng S, Liu B. Nonconserved miR-608 suppresses prostate cancer progression through RAC2/PAK4/LIMK1 and BCL2L1/caspase-3 pathways by targeting the 3'-UTRs of RAC2/BCL2L1 and the coding region of PAK4. Cancer Med 2019; 8:5716-5734. [PMID: 31389670 PMCID: PMC6746107 DOI: 10.1002/cam4.2455] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 06/27/2019] [Accepted: 07/13/2019] [Indexed: 01/02/2023] Open
Abstract
The aim of this study is to investigate the functions and mechanisms of miR-608 in prostate cancer (PCa). CISH and qRT-PCR analysis demonstrated that miR-608 was low expressed in PCa tissues and cells, which was partly attributed to the methylation of CpG island adjacent to the transcription start site (TSS) of miR-608 gene. Intracellular miR-608 overexpression inhibited in vivo PCa tumor growth, and suppressed PCa cell proliferation, G2/M transition, and migration in vitro, which was independent of EMT-associated mechanisms. Then RAC2, a GTPase previously deemed hematopoiesis-specific but now discovered to exist and play important roles in PCa, was verified by western blot and dual-luciferase reporter assays to mediate the effects of miR-608 through RAC2/PAK4/LIMK1/cofilin pathway. MiR-608 also promoted the apoptosis of PCa cells through BCL2L1/caspase-3 pathway by targeting the 3'-UTR of BCL2L1. Moreover, PAK4, the downstream effector of RAC2, was found to be targeted by miR-608 at the mRNA coding sequence (CDS) instead of the canonical 3'-UTR. Knocking down RAC2, PAK4, or BCL2L1 with siRNAs reproduced the antiproliferative, mitosis-obstructive, antimigratory and proapoptotic effects of miR-608 in PCa cells, which could be attenuated by downregulating miR-608. In conclusion, miR-608 suppresses PCa progression, and its activation provides a new therapeutic option for PCa.
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Affiliation(s)
- Xu Zhang
- Department of Urologythe First Affiliated Hospital, Zhejiang University School of MedicineHangzhouChina
| | - Jiajie Fang
- Department of Urologythe First Affiliated Hospital, Zhejiang University School of MedicineHangzhouChina
| | - Shiming Chen
- Department of Urologythe First Affiliated Hospital, Zhejiang University School of MedicineHangzhouChina
| | - Weiyu Wang
- Department of Urologythe First Affiliated Hospital, Zhejiang University School of MedicineHangzhouChina
| | - Shuai Meng
- Department of UrologyZhejiang Provincial People's HospitalHangzhouChina
| | - Ben Liu
- Department of Urologythe First Affiliated Hospital, Zhejiang University School of MedicineHangzhouChina
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27
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Sun X, Su VL, Calderwood DA. The subcellular localization of type I p21-activated kinases is controlled by the disordered variable region and polybasic sequences. J Biol Chem 2019; 294:14319-14332. [PMID: 31391252 DOI: 10.1074/jbc.ra119.007692] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 07/30/2019] [Indexed: 12/20/2022] Open
Abstract
p21-activated kinases (PAKs) are serine/threonine kinase effectors of the small GTPases Rac and Cdc42 and major participants in cell adhesion, motility, and survival. Type II PAKs (PAK4, -5, and -6) are recruited to cell-cell boundaries, where they regulate adhesion dynamics and colony escape. In contrast, the type I PAK, PAK1, does not localize to cell-cell contacts. We have now found that the other type I PAKs (PAK2 and PAK3) also fail to target to cell-cell junctions. PAKs contain extensive similarities in sequence and domain organization; therefore, focusing on PAK1 and PAK6, we used chimeras and truncation mutants to investigate their differences in localization. We observed that a weakly conserved sequence region (the variable region), located between the Cdc42-binding CRIB domain and the kinase domain, inhibits PAK1 targeting to cell-cell junctions. Accordingly, substitution of the PAK1 variable region with that from PAK6 or removal of this region of PAK1 resulted in its localization to cell-cell contacts. We further show that Cdc42 binding is required, but not sufficient, to direct PAKs to cell-cell contacts and that an N-terminal polybasic sequence is necessary for PAK1 recruitment to cell-cell contacts, but only if the variable region-mediated inhibition is released. We propose that all PAKs contain cell-cell boundary-targeting motifs but that the variable region prevents type I PAK accumulation at junctions. This highlights the importance of this poorly conserved, largely disordered region in PAK regulation and raises the possibility that variable region inhibition may be released by cellular signals.
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Affiliation(s)
- Xiaowen Sun
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520
| | - Valerie L Su
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520
| | - David A Calderwood
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520.,Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06520
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28
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Das S, Nair RS, Mishra R, Sondarva G, Viswakarma N, Abdelkarim H, Gaponenko V, Rana B, Rana A. Mixed lineage kinase 3 promotes breast tumorigenesis via phosphorylation and activation of p21-activated kinase 1. Oncogene 2019; 38:3569-3584. [PMID: 30664689 PMCID: PMC7568686 DOI: 10.1038/s41388-019-0690-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 11/28/2018] [Accepted: 12/07/2018] [Indexed: 02/03/2023]
Abstract
Mixed lineage kinase 3 (MLK3), a MAP3K member has been envisioned as a viable drug target in cancer, yet its detailed function and signaling is not fully elucidated. We identified that MLK3 tightly associates with an oncogene, PAK1. Mammalian PAK1 being a Ste20 (MAP4K) member, we tested whether it is an upstream regulator of MLK3. In contrast to our hypothesis, MLK3 activated PAK1 kinase activity directly, as well as in the cells. Although, MLK3 can phosphorylate PAK1 on Ser133 and Ser204 sites, PAK1S133A mutant is constitutively active, whereas, PAK1S204A is not activated by MLK3. Stable overexpression of PAK1S204A in breast cancer cells, impedes migration, invasion, and NFĸB activity. In vivo breast cancer cell tumorigenesis is significantly reduced in tumors expressing PAK1S204A mutant. These results suggest that mammalian PAK1 does not act as a MAP4K and MLK3-induced direct activation of PAK1 plays a key role in breast cancer tumorigenesis.
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Affiliation(s)
- Subhasis Das
- Department of Surgery, Division of Surgical Oncology, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Rakesh Sathish Nair
- Department of Surgery, Division of Surgical Oncology, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Rajakishore Mishra
- Center for Life Sciences, School of Natural Sciences, Central University of Jharkhand, Ranchi, Jharkhand, 835205, India
| | - Gautam Sondarva
- Department of Surgery, Division of Surgical Oncology, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Navin Viswakarma
- Department of Surgery, Division of Surgical Oncology, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Hazem Abdelkarim
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - Vadim Gaponenko
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - Basabi Rana
- Department of Surgery, Division of Surgical Oncology, University of Illinois at Chicago, Chicago, IL, 60612, USA
- University of Illinois Hospital &Health Sciences System Cancer Center, University of Illinois at Chicago, Chicago, IL, 60612, USA
- Jesse Brown VA Medical Center, Chicago, IL, 60612, USA
| | - Ajay Rana
- Department of Surgery, Division of Surgical Oncology, University of Illinois at Chicago, Chicago, IL, 60612, USA.
- University of Illinois Hospital &Health Sciences System Cancer Center, University of Illinois at Chicago, Chicago, IL, 60612, USA.
- Jesse Brown VA Medical Center, Chicago, IL, 60612, USA.
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29
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Solution structures and biophysical analysis of full-length group A PAKs reveal they are monomeric and auto-inhibited in cis. Biochem J 2019; 476:1037-1051. [PMID: 30858169 PMCID: PMC6448136 DOI: 10.1042/bcj20180867] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 03/05/2019] [Accepted: 03/08/2019] [Indexed: 12/13/2022]
Abstract
The group A p21-activated kinases (PAKs) exist in an auto-inhibited form until activated by GTPase binding and auto-phosphorylation. In the auto-inhibited form, a regulatory domain binds to the kinase domain (KD) blocking the binding of substrates, and CDC42 or Rac binding to the regulatory domain relieves this auto-inhibition allowing auto-phosphorylation on the KD activation loop. We have determined the crystal structure of the PAK3 catalytic domain and by small angle X-ray scattering, the solution-phase structures of full-length inactive PAK1 and PAK3. The structures reveal a compact but elongated molecular shape that demonstrates that, together with multiple independent biophysical measurements and in contrast with previous assumptions, group A PAKs are monomeric both before and after activation, consistent with an activation mechanism of cis-auto-inhibition and initial cis-auto-phosphorylation, followed by transient dimerisation to allow trans-auto-phosphorylation for full activation, yielding a monomeric active PAK protein.
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30
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Inhibition of PAK1 alleviates cerulein-induced acute pancreatitis via p38 and NF-κB pathways. Biosci Rep 2019; 39:BSR20182221. [PMID: 30718368 PMCID: PMC6395303 DOI: 10.1042/bsr20182221] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 01/25/2019] [Accepted: 01/29/2019] [Indexed: 12/11/2022] Open
Abstract
Acute pancreatitis is a life-threatening disease accompanied by systemic inflammatory response. NF-κB and p38 signal pathways are activated in AP induced by cerulein. And PAKs are multifunctional effectors of Rho GTPases with kinase activity. In the present study, the function of P21-activated kinase 1 (PAK1) in AP was investigated, and found that PAK1 was up-regulated in pancreas of AP mice model, and led to NF-κB and p38 pathway activation. PAK1 inhibition by shRNA or small molecule inhibitor FRAX597 decreased NF-κB and p38 activity, also alleviated the pathological damage in the pancreas of AP mice model, including decreasing the amylase and lipase levels in serum, decreasing the levels of tumor necrosis factor-α, interleukin-6, and interleukin-1β in AP. These results suggested that PAK1 inhibition protects against AP by inhibiting NF-κB and p38 pathways, and indicated that PAK1 is a potential therapy to alleviate AP patients in clinic, and these need to be explored further.
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31
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Onwubiko UN, Mlynarczyk PJ, Wei B, Habiyaremye J, Clack A, Abel SM, Das ME. A Cdc42 GEF, Gef1, through endocytosis organizes F-BAR Cdc15 along the actomyosin ring and promotes concentric furrowing. J Cell Sci 2019; 132:jcs223776. [PMID: 30709916 PMCID: PMC6432710 DOI: 10.1242/jcs.223776] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 01/21/2019] [Indexed: 01/17/2023] Open
Abstract
During cytokinesis, fission yeast coordinates actomyosin ring constriction with septum ingression, resulting in concentric furrow formation by a poorly defined mechanism. We report that Schizosaccharomyces pombe cells lacking the Cdc42 activator Gef1, combined with an activated allele of the formin, Cdc12, display non-concentric furrowing. Non-concentrically furrowing cells display uneven distribution of the scaffold Cdc15 along the ring. This suggests that, after ring assembly, uniform Cdc15 distribution along the ring enables proper furrow formation. We find that, after assembly, Cdc15 is recruited to the ring in an Arp2/3 complex-dependent manner and is decreased in the activated cdc12 mutant. Cdc15 at cortical endocytic patches shows increased levels and extended lifetimes in gef1 and activated cdc12 mutants. We hypothesize endocytosis helps recruit Cdc15 to assembled rings; uneven Cdc15 distribution at the ring occurs when endocytic patches contain increased Cdc15 levels and the patch-association rate is slow. Based on this, we developed a mathematical model that captures experimentally observed Cdc15 distributions along the ring. We propose that, at the ring, Gef1 and endocytic events promote uniform Cdc15 organization to enable proper septum ingression and concentric furrow formation.
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Affiliation(s)
- Udo N Onwubiko
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Paul J Mlynarczyk
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996, USA
| | - Bin Wei
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Julius Habiyaremye
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Amanda Clack
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Steven M Abel
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996, USA
| | - Maitreyi E Das
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
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32
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Activating Mutations in PAK1, Encoding p21-Activated Kinase 1, Cause a Neurodevelopmental Disorder. Am J Hum Genet 2018; 103:579-591. [PMID: 30290153 DOI: 10.1016/j.ajhg.2018.09.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 09/10/2018] [Indexed: 12/20/2022] Open
Abstract
p21-activated kinases (PAKs) are serine/threonine protein kinases acting as effectors of CDC42 and RAC, which are members of the RHO family of small GTPases. PAK1's kinase activity is autoinhibited by homodimerization, whereas CDC42 or RAC1 binding causes PAK1 activation by dimer dissociation. Major functions of the PAKs include actin cytoskeleton reorganization, for example regulation of the cellular protruding activity during cell spreading. We report the de novo PAK1 mutations c.392A>G (p.Tyr131Cys) and c.1286A>G (p.Tyr429Cys) in two unrelated subjects with developmental delay, secondary macrocephaly, seizures, and ataxic gait. We identified enhanced phosphorylation of the PAK1 targets JNK and AKT in fibroblasts of one subject and of c-JUN in those of both subjects compared with control subjects. In fibroblasts of the two affected individuals, we observed a trend toward enhanced PAK1 kinase activity. By using co-immunoprecipitation and size-exclusion chromatography, we observed a significantly reduced dimerization for both PAK1 mutants compared with wild-type PAK1. These data demonstrate that the two PAK1 variants function as activating alleles. In a cell spreading assay, subject-derived fibroblasts showed significant enrichment in cells occupied by filopodia. Interestingly, application of the PAK1 inhibitor FRAX486 completely reversed this cellular phenotype. Together, our data reveal that dominantly acting, gain-of-function PAK1 mutations cause a neurodevelopmental phenotype with increased head circumference, possibly by a combined effect of defective homodimerization and enhanced kinase activity of PAK1. This condition, along with the developmental disorders associated with RAC1 and CDC42 missense mutations, highlight the importance of RHO GTPase members and effectors in neuronal development.
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33
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Lajkó DB, Valkai I, Domoki M, Ménesi D, Ferenc G, Ayaydin F, Fehér A. In silico identification and experimental validation of amino acid motifs required for the Rho-of-plants GTPase-mediated activation of receptor-like cytoplasmic kinases. PLANT CELL REPORTS 2018; 37:627-639. [PMID: 29340786 DOI: 10.1007/s00299-018-2256-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 01/08/2018] [Indexed: 06/07/2023]
Abstract
Several amino acid motifs required for Rop-dependent activity were found to form a common surface on RLCKVI_A kinases. This indicates a unique mechanism for Rho-type GTPase-mediated kinase activation in plants. Rho-of-plants (Rop) G-proteins are implicated in the regulation of various cellular processes, including cell growth, cell polarity, hormonal and pathogen responses. Our knowledge about the signalling pathways downstream of Rops is continuously increasing. However, there are still substantial gaps in this knowledge. One reason for this is that these pathways are considerably different from those described for yeast and/or animal Rho-type GTPases. Among others, plants lack all Rho/Rac/Cdc42-activated kinase families. Only a small group of plant-specific receptor-like cytoplasmic kinases (RLCK VI_A) has been shown to exhibit Rop-binding-dependent in vitro activity. These kinases do not carry any known GTPase-binding motifs. Based on the sequence comparison of the Rop-activated RLCK VI_A and the closely related but constitutively active RLCK VI_B kinases, several distinguishing amino acid residues/motifs were identified. All but one of these were found to be required for the Rop-mediated regulation of the in vitro activity of two RLCK VI_A kinases. Structural modelling indicated that these motifs might form a common Rop-binding surface. Based on in silico data mining, kinases that have the identified Rop-binding motifs are present in Embryophyta but not in unicellular green algae. It can, therefore, be supposed that Rops recruited these plant-specific kinases for signalling at an early stage of land plant evolution.
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Affiliation(s)
- Dézi Bianka Lajkó
- Biological Research Centre, Institute of Plant Biology, Hungarian Academy of Sciences, Temesvári krt. 62, P.O. Box 521, Szeged, 6701, Hungary
| | - Ildikó Valkai
- Biological Research Centre, Institute of Plant Biology, Hungarian Academy of Sciences, Temesvári krt. 62, P.O. Box 521, Szeged, 6701, Hungary
| | - Mónika Domoki
- Biological Research Centre, Institute of Plant Biology, Hungarian Academy of Sciences, Temesvári krt. 62, P.O. Box 521, Szeged, 6701, Hungary
| | - Dalma Ménesi
- Biological Research Centre, Institute of Plant Biology, Hungarian Academy of Sciences, Temesvári krt. 62, P.O. Box 521, Szeged, 6701, Hungary
| | - Györgyi Ferenc
- Biological Research Centre, Institute of Plant Biology, Hungarian Academy of Sciences, Temesvári krt. 62, P.O. Box 521, Szeged, 6701, Hungary
| | - Ferhan Ayaydin
- Biological Research Centre, Institute of Plant Biology, Hungarian Academy of Sciences, Temesvári krt. 62, P.O. Box 521, Szeged, 6701, Hungary
| | - Attila Fehér
- Biological Research Centre, Institute of Plant Biology, Hungarian Academy of Sciences, Temesvári krt. 62, P.O. Box 521, Szeged, 6701, Hungary.
- Department of Plant Biology, University of Szeged, Közép fasor 52, Szeged, 6726, Hungary.
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Abstract
The p21-activated kinase (PAK) group of serine/threonine kinases are downstream effectors of RHO GTPases and play important roles in regulation of the actin cytoskeleton, cell growth, survival, polarity, and development. Here we probe the interaction of the type II PAK, PAK4, with RHO GTPases. Using solution scattering we find that the full-length PAK4 heterodimer with CDC42 adopts primarily a compact organization. X-ray crystallography reveals the molecular nature of the interaction between PAK4 and CDC42 and shows that in addition to the canonical PAK4 CDC42/RAC interactive binding (CRIB) domain binding to CDC42 there are unexpected contacts involving the PAK4 kinase C-lobe, CDC42, and the PAK4 polybasic region. These additional interactions modulate kinase activity and increase the binding affinity of CDC42 for full-length PAK4 compared with the CRIB domain alone. We therefore show that the interaction of CDC42 with PAK4 can influence kinase activity in a previously unappreciated manner.
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Abstract
Schizophrenia is a complex disorder lacking an effective treatment option for the pervasive and debilitating cognitive impairments experienced by patients. Working memory is a core cognitive function impaired in schizophrenia that depends upon activation of distributed neural network, including the circuitry of the dorsolateral prefrontal cortex (DLPFC). Accordingly, individuals diagnosed with schizophrenia show reduced DLPFC activation while performing working-memory tasks. This lower DLPFC activation appears to be an integral part of the disease pathophysiology, and not simply a reflection of poor performance. Thus, the cellular and circuitry alterations that underlie lower DLPFC neuronal activity in schizophrenia must be determined in order to identify appropriate therapeutic targets. Studies using human postmortem brain tissue provide a robust way to investigate and characterize these cellular and circuitry alterations at multiple levels of resolution, and such studies provide essential information that cannot be obtained either through in vivo studies in humans or through experimental animal models. Studies examining neuronal morphology, protein expression and localization, and transcript levels indicate that a microcircuit composed of excitatory pyramidal cells and inhibitory interneurons containing the calcium-binding protein parvalbumin is altered in the DLPFC of subjects with schizophrenia and likely contributes to DLPFC dysfunction.
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Affiliation(s)
- Jill R Glausier
- Translational Neuroscience Program, Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, United States
| | - David A Lewis
- Translational Neuroscience Program, Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, United States.
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36
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Cloning and functional characterization of human Pak1 promoter by steroid hormones. Gene 2017; 646:120-128. [PMID: 29274909 DOI: 10.1016/j.gene.2017.12.039] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 10/29/2017] [Accepted: 12/20/2017] [Indexed: 12/21/2022]
Abstract
P21-activated kinase 1 (Pak1) is known to be involved in a plethora of functions including cell growth, survival and can lead to cell transformation and tumor progression especially in breast tissue. Multiple studies have shown Pak1 dysregulation as a change in DNA copy number as well as gene expression levels, suggesting many regulatory mechanisms at transcriptional and translational level. However, very little is known about the transcriptional regulation of the human Pak1 promoter. Here, we focus on Pak1 promoter regulation by steroid hormones along with their respective receptors that are also crucial players in breast tissue function and tumorigenesis. Our results show high Pak1 expression in breast cancer cell lines and in breast tumor tissue. It also suggests that Pak1 is hormone responsive, whose expression can be modulated by steroid hormones namely, estrogen in the form of 17β-estradiol (E2) and progesterone (P4). Sequence analysis of a 3.2kb Pak1 proximal promoter region shows the presence of PRE (progesterone response element) and ERE (estrogen response element) half sites, that were further cloned and characterized. Results from promoter analysis showed that Pak1 promoter activity is mediated by PR via its binding to PRE present on the Pak1 promoter that was further reaffirmed in vitro by electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation assay (ChIP). Our results together suggest that it is the PR isoform B regulates Pak1 promoter. To our knowledge, this is the first study to report the detailed characterization and transcriptional regulation of the human Pak1 promoter by steroid hormones.
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Liu F, Cheng Z, Li X, Li Y, Zhang H, Li J, Liu F, Xu H, Li F. A Novel Pak1/ATF2/miR-132 Signaling Axis Is Involved in the Hematogenous Metastasis of Gastric Cancer Cells. MOLECULAR THERAPY. NUCLEIC ACIDS 2017; 8:370-382. [PMID: 28918037 PMCID: PMC5537170 DOI: 10.1016/j.omtn.2017.07.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 07/04/2017] [Accepted: 07/05/2017] [Indexed: 12/21/2022]
Abstract
We, along with others, have shown previously that P21-activated kinase 1 (Pak1) plays a pivotal role in gastric cancer progression and metastasis. However, whether Pak1 controls gastric cancer metastasis by regulating microRNAs (miRNAs) has never been explored. Here, we report a novel mechanism of Pak1 in tumor metastasis. A detailed examination revealed that Pak1 interacts with and phosphorylates the serine 62 residue of ATF2 and then blocks its translocation into the nucleus. We also confirmed that ATF2 binds to the promoter of miR-132 and tightly regulates its transcription, thus explaining the regulatory mechanism of miR-132 by Pak1. miR-132 also significantly reduced cell adhesion, migration, and invasion of gastric cancer cells in vitro and significantly prevented tumor metastasis in vivo. miR-132 specifically inhibited hematogenous metastasis, but not lymph node or implantation metastases. In order to further delineate the effects of the Pak1/ATF2/miR-132 cascade on gastric cancer progression, we identified several targets of miR-132 using a bioinformatics TargetScan algorithm. Notably, miR-132 reduced the expression of CD44 and fibronectin1 (FN1), and such inhibition enabled lymphocytes to home in on gastric cancer cells and induce tumor apoptosis. Taken together, our studies establish a novel cell-signaling pathway and open new possibilities for therapeutic intervention of gastric cancer.
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Affiliation(s)
- Funan Liu
- Department of Cell Biology, Key Laboratory of Cell Biology, Ministry of Public Health and Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang 110122, China; Department of Surgical Oncology and General Surgery, The First Affiliated Hospital of China Medical University, Shenyang 110122, China
| | - Zhenguo Cheng
- Department of Cell Biology, Key Laboratory of Cell Biology, Ministry of Public Health and Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang 110122, China
| | - Xiaodong Li
- Department of Cell Biology, Key Laboratory of Cell Biology, Ministry of Public Health and Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang 110122, China
| | - Yanshu Li
- Department of Cell Biology, Key Laboratory of Cell Biology, Ministry of Public Health and Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang 110122, China
| | - Hongyan Zhang
- Department of Cell Biology, Key Laboratory of Cell Biology, Ministry of Public Health and Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang 110122, China
| | - Jiabin Li
- Department of Cell Biology, Key Laboratory of Cell Biology, Ministry of Public Health and Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang 110122, China
| | - Furong Liu
- Department of Cell Biology, Key Laboratory of Cell Biology, Ministry of Public Health and Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang 110122, China
| | - Huimian Xu
- Department of Surgical Oncology and General Surgery, The First Affiliated Hospital of China Medical University, Shenyang 110122, China
| | - Feng Li
- Department of Cell Biology, Key Laboratory of Cell Biology, Ministry of Public Health and Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang 110122, China.
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38
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Abstract
p21-Activated kinase 1 (PAK1) has attracted much attention as a potential therapeutic target due to its central role in many oncogenic signaling pathways, its frequent dysregulation in cancers and neurological disorders, and its tractability as a target for small-molecule inhibition. To date, several PAK1-targeting compounds have been developed as preclinical agents, including one that has been evaluated in a clinical trial. A series of ATP-competitive inhibitors, allosteric inhibitors and peptide inhibitors with distinct biochemical and pharmacokinetic properties represent useful laboratory tools for studies on the role of PAK1 in biology and in disease contexts, and could lead to promising therapeutic agents. Given the central role of PAK1 in vital signaling pathways, future clinical development of PAK1 inhibitors will require careful investigation of their safety and efficacy.
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Wang Y, Wang S, Lei M, Boyett M, Tsui H, Liu W, Wang X. The p21-activated kinase 1 (Pak1) signalling pathway in cardiac disease: from mechanistic study to therapeutic exploration. Br J Pharmacol 2017; 175:1362-1374. [PMID: 28574147 DOI: 10.1111/bph.13872] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 05/12/2017] [Accepted: 05/17/2017] [Indexed: 01/01/2023] Open
Abstract
p21-activated kinase 1 (Pak1) is a member of the highly conserved family of serine/threonine protein kinases regulated by Ras-related small G-proteins, Cdc42/Rac1. It has been previously demonstrated to be involved in cardiac protection. Based on recent studies, this review provides an overview of the role of Pak1 in cardiac diseases including disrupted Ca2+ homoeostasis-related cardiac arrhythmias, adrenergic stress- and pressure overload-induced hypertrophy, and ischaemia/reperfusion injury. These findings demonstrate the important role of Pak1 mediated through the phosphorylation and transcriptional modification of hypertrophy and/or arrhythmia-related genes. This review also discusses the anti-arrhythmic and anti-hypertrophic, protective function of Pak1 and the beneficial effects of fingolimod (an FDA-approved sphingolipid drug), a Pak1 activator, and its ability to prevent arrhythmias and cardiac hypertrophy. These findings also highlight the therapeutic potential of Pak1 signalling in the treatment and prevention of cardiac diseases. LINKED ARTICLES This article is part of a themed section on Spotlight on Small Molecules in Cardiovascular Diseases. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.8/issuetoc.
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Affiliation(s)
- Yanwen Wang
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Shunyao Wang
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Ming Lei
- Department of Pharmacology, The University of Oxford, Oxford, UK
| | - Mark Boyett
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Hoyee Tsui
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Wei Liu
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Xin Wang
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
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Receptor-stimulated transamidation induces activation of Rac1 and Cdc42 and the regulation of dendritic spines. Neuropharmacology 2017; 117:93-105. [PMID: 28161375 DOI: 10.1016/j.neuropharm.2017.01.034] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 01/26/2017] [Accepted: 01/29/2017] [Indexed: 11/21/2022]
Abstract
Regulation of dendritic spines is an important component of synaptic function and plasticity whereas dendritic spine dysregulation is related to several psychiatric and neurological diseases. In the present study, we tested the hypothesis that serotonin (5-HT)2A/2C receptor-induced Rho family transamidation and activation regulates dendritic spine morphology and that activation of multiple types of receptors can induce transglutaminase (TGase)-catalyzed transamidation of small G proteins. We previously reported a novel 5-HT2A receptor downstream effector, TGase-catalyzed serotonylation of the small G protein Rac1 in A1A1v cells, a rat embryonic cortical cell line. We now extend these findings to rat primary cortical cultures which develop dendritic spines; stimulation of 5-HT2A/2C receptors increased transamidation of Rac1 and Cdc42, but not RhoA. Inhibition of TGases significantly decreased transamidation and activation of Rac1 and Cdc42, suggesting that transamidation led to their activation. In primary cortical cultures, stimulation of 5-HT2A/2C receptors by 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) caused a transient dendritic spine enlargement, which was blocked by TGase inhibition. Stimulation of both 5-HT2A and 5-HT2C receptors contributed to DOI-induced Rac1 transamidation in primary cortical cultures as demonstrated by selective antagonists. Furthermore, stimulation of muscarinic acetylcholine receptors and NMDA receptors also increased TGase-catalyzed Rac1 activation in SH-SY5Y cells and N2a cells, respectively. Receptor-stimulated TGase-catalyzed transamidation of Rac1 occurs at Q61, a site previously reported to be important in the inactivation of Rac1. These studies demonstrate that TGase-catalyzed transamidation and activation of small G proteins results from stimulation of multiple types of receptors and this novel signaling pathway can regulate dendritic spine morphology and plasticity.
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41
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Tunduguru R, Thurmond DC. Promoting Glucose Transporter-4 Vesicle Trafficking along Cytoskeletal Tracks: PAK-Ing Them Out. Front Endocrinol (Lausanne) 2017; 8:329. [PMID: 29209279 PMCID: PMC5701999 DOI: 10.3389/fendo.2017.00329] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 11/06/2017] [Indexed: 12/27/2022] Open
Abstract
Glucose is the principal cellular energy source in humans and maintenance of glucose homeostasis is critical for survival. Glucose uptake into peripheral skeletal muscle and adipose tissues requires the trafficking of vesicles containing glucose transporter-4 (GLUT4) from the intracellular storage compartments to the cell surface. Trafficking of GLUT4 storage vesicles is initiated via the canonical insulin signaling cascade in skeletal muscle and fat cells, as well as via exercise-induced contraction in muscle cells. Recent studies have elucidated steps in the signaling cascades that involve remodeling of the cytoskeleton, a process that underpins the mechanical movement of GLUT4 vesicles. This review is focused upon an alternate phosphoinositide-3 kinase-dependent pathway involving Ras-related C3 botulinum toxin substrate 1 signaling through the p21-activated kinase p21-activated kinase 1 and showcases related signaling events that co-regulate both the depolymerization and re-polymerization of filamentous actin. These new insights provide an enriched understanding into the process of glucose transport and yield potential new targets for interventions aimed to improve insulin sensitivity and remediate insulin resistance, pre-diabetes, and the progression to type 2 diabetes.
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Affiliation(s)
- Ragadeepthi Tunduguru
- Department of Molecular and Cellular Endocrinology, Diabetes and Metabolism Research Institute of City of Hope, Duarte, CA, United States
| | - Debbie C. Thurmond
- Department of Molecular and Cellular Endocrinology, Diabetes and Metabolism Research Institute of City of Hope, Duarte, CA, United States
- *Correspondence: Debbie C. Thurmond,
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42
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Molecular Insights and Functional Implication of LRRK2 Dimerization. ADVANCES IN NEUROBIOLOGY 2017; 14:107-121. [DOI: 10.1007/978-3-319-49969-7_6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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43
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The guanine nucleotide exchange factor Net1 facilitates the specification of dorsal cell fates in zebrafish embryos by promoting maternal β-catenin activation. Cell Res 2016; 27:202-225. [PMID: 27910850 DOI: 10.1038/cr.2016.141] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Revised: 09/18/2016] [Accepted: 09/27/2016] [Indexed: 12/14/2022] Open
Abstract
Wnt/β-catenin signaling is essential for the initiation of dorsal-ventral patterning during vertebrate embryogenesis. Maternal β-catenin accumulates in dorsal marginal nuclei during cleavage stages, but its critical target genes essential for dorsalization are silent until mid-blastula transition (MBT). Here, we find that zebrafish net1, a guanine nucleotide exchange factor, is specifically expressed in dorsal marginal blastomeres after MBT, and acts as a zygotic factor to promote the specification of dorsal cell fates. Loss- and gain-of-function experiments show that the GEF activity of Net1 is required for the activation of Wnt/β-catenin signaling in zebrafish embryos and mammalian cells. Net1 dissociates and activates PAK1 dimers, and PAK1 kinase activation causes phosphorylation of S675 of β-catenin after MBT, which ultimately leads to the transcription of downstream target genes. In summary, our results reveal that Net1-regulated β-catenin activation plays a crucial role in the dorsal axis formation during zebrafish development.
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44
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Song L, Wang F, Dong Z, Hua X, Xia Q. Label-free quantitative phosphoproteomic profiling of cellular response induced by an insect cytokine paralytic peptide. J Proteomics 2016; 154:49-58. [PMID: 27903465 DOI: 10.1016/j.jprot.2016.11.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Revised: 11/18/2016] [Accepted: 11/21/2016] [Indexed: 12/18/2022]
Abstract
Paralytic peptide (PP) participates in diverse physiological processes as an insect cytokine, such as immunity control, paralysis induction, regulation of cell morphology and proliferation. To investigate the molecular mechanism underlying those physiological activities, we systematically investigated the global phosphorylation events in fat body of silkworm larvae induced by PP through label-free quantitative phosphoproteomics. 2534 phosphosites were finally identified, of which the phosphorylation level of 620 phosphosites on 244 proteins was significantly up-regulated and 67 phosphosites on 43 proteins was down-regulated. Among those proteins, 13 were protein kinases (PKs), 13 were transcription factors (TFs) across 10 families and 17 were metabolism related enzymes. Meanwhile, Motif-X analysis of the phosphorylation sites showed that 16 motifs are significantly enriched, including 8 novel phosphorylation motifs. In addition, KEGG and functional interacting network analysis revealed that phosphorylation cascades play the crucial regulation roles in PP-dependent signaling pathways, and highlighted the potential central position of the mitogen-activated protein kinases (MAPKs) in them. These analyses provide direct insights into the molecule mechanisms of cellular response induced by PP. SIGNIFICANCE PP as an insect cytokine participated in diverse functions including immunity control paralysis induction, regulation of cell morphology and proliferation. In this study, we performed firstly a label-free quantitative phosphoproteomics analysis. We found some new phosphorylation targets of PP-stimulation. Meanwhile, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis and functional networks revealed that phosphorylation cascades play the crucial regulation roles in PP-dependent signaling pathways. In addition, the potential central position of the mitogen-activated protein kinases (MAPKs) was highlighted in PP-dependent signaling pathways. We think our findings may help us gain a systematic understanding of the cytokine-dependent response regulation in insects.
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Affiliation(s)
- Liang Song
- State Key Laboratory of Silkworm Genome Biology, Southwest University, 216, Tiansheng Road, Beibei, Chongqing 400716, China.
| | - Fei Wang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, 216, Tiansheng Road, Beibei, Chongqing 400716, China.
| | - Zhaoming Dong
- State Key Laboratory of Silkworm Genome Biology, Southwest University, 216, Tiansheng Road, Beibei, Chongqing 400716, China.
| | - Xiaoting Hua
- State Key Laboratory of Silkworm Genome Biology, Southwest University, 216, Tiansheng Road, Beibei, Chongqing 400716, China.
| | - Qingyou Xia
- State Key Laboratory of Silkworm Genome Biology, Southwest University, 216, Tiansheng Road, Beibei, Chongqing 400716, China.
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45
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PAK5 is auto-activated by a central domain that promotes kinase oligomerization. Biochem J 2016; 473:1777-89. [DOI: 10.1042/bcj20160132] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 04/18/2016] [Indexed: 12/23/2022]
Abstract
The present study shows for the first time that self-association of PAK5 in vivo underlies its high basal activity, which contrasts with the inactive state of cellular PAK4. Such PAK5 self-association interferes with the engagement of the auto-inhibitory (AID) with the catalytic domain.
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46
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Lazzari C, Verlicchi A, Gkountakos A, Pilotto S, Santarpia M, Chaib I, Ramirez Serrano JL, Viteri S, Morales-Espinosa D, Dazzi C, de Marinis F, Cao P, Karachaliou N, Rosell R. Molecular Bases for Combinatorial Treatment Strategies in Patients with KRAS Mutant Lung Adenocarcinoma and Squamous Cell Lung Carcinoma. Pulm Ther 2016. [DOI: 10.1007/s41030-016-0013-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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47
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PAK1-mediated MORC2 phosphorylation promotes gastric tumorigenesis. Oncotarget 2016; 6:9877-86. [PMID: 25888627 PMCID: PMC4496403 DOI: 10.18632/oncotarget.3185] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2014] [Accepted: 01/23/2015] [Indexed: 01/10/2023] Open
Abstract
To date, microrchidia (MORC) family CW-type zinc-finger 2 (MORC2), has been found to be involved in p21-activated kinase1 (PAK1) pathway to maintain genomic integrity. Here, we explore its novel role in cancer. We demonstrate that PAK1-mediated MORC2 phosphorylation promotes cell cycle progression, defective phosphorylation of MORC2-S677A results in attenuated cell proliferation and tumorigenicity of gastric cancer cells, which is significantly enhanced in overexpression of phospho-mimic MORC2-S677E form, suggesting the importance of MORC2 phosphorylation in tumorigenesis. More importantly, phosphorylation of MORC2 correlates positively with PAK1 expression in clinical gastric cancer. Furthermore, high expression of PAK1 and phosphorylation of MORC2 appear to be associated with poor prognosis of clinical gastric cancer. Collectively, these findings revealed a novel function of MORC2 phosphorylation in promoting gastric cell proliferation in vitro and tumorigenesis in vivo, suggesting that blocking PAK1-mediated MORC2 phosphorylation might be a potential therapeutic strategy for gastric tumorigenesis.
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48
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Ijuin T, Hatano N, Hosooka T, Takenawa T. Regulation of insulin signaling in skeletal muscle by PIP3 phosphatase, SKIP, and endoplasmic reticulum molecular chaperone glucose-regulated protein 78. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:3192-201. [DOI: 10.1016/j.bbamcr.2015.09.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 09/08/2015] [Accepted: 09/10/2015] [Indexed: 12/30/2022]
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49
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Datta D, Arion D, Corradi JP, Lewis DA. Altered expression of CDC42 signaling pathway components in cortical layer 3 pyramidal cells in schizophrenia. Biol Psychiatry 2015; 78:775-85. [PMID: 25981171 PMCID: PMC4600637 DOI: 10.1016/j.biopsych.2015.03.030] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 03/30/2015] [Accepted: 03/30/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND Cognitive dysfunction in schizophrenia is associated with a lower density of dendritic spines on deep layer 3 pyramidal cells in the dorsolateral prefrontal cortex (DLPFC). These alterations appear to reflect dysregulation of the actin cytoskeleton required for spine formation and maintenance. Consistent with this idea, altered expression of genes in the cell division cycle 42 (CDC42)-CDC42 effector protein (CDC42EP) signaling pathway, a key organizer of the actin cytoskeleton, was previously reported in DLPFC gray matter from subjects with schizophrenia. We examined the integrity of the CDC42-p21-activated serine/threonine protein kinases (PAK)-LIM domain-containing serine/threonine protein kinases (LIMK) signaling pathway in schizophrenia in a layer-specific and cell type-specific fashion in DLPFC deep layer 3. METHODS Using laser microdissection, samples of DLPFC deep layer 3 were collected from 56 matched pairs of subjects with schizophrenia and comparison subjects, and levels of CDC42-PAK-LIMK pathway messenger RNAs were measured by quantitative polymerase chain reaction. These same transcripts also were quantified by microarray in samples of individually microdissected deep layer 3 pyramidal cells from a subset of the same subjects and from monkeys exposed to antipsychotics. RESULTS Relative to comparison subjects, CDC42EP4, LIMK1, LIMK2, ARHGDIA, and PAK3 messenger RNA levels were significantly upregulated in subjects with schizophrenia in laminar and cellular samples. In contrast, CDC42 and PAK1 messenger RNA levels were significantly downregulated specifically in deep layer 3 pyramidal cells. These differences were not attributable to psychotropic medications or other comorbid factors. CONCLUSIONS Findings from the present and prior studies converge on synergistic alterations in CDC42 signaling pathway that could destabilize actin dynamics and produce spine deficits preferentially in deep layer 3 pyramidal cells in schizophrenia.
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Affiliation(s)
- Dibyadeep Datta
- Department of Neuroscience, University of Pittsburgh School of Medicine,Translational Neuroscience Program, University of Pittsburgh School of Medicine
| | - Dominique Arion
- Department of Psychiatry, University of Pittsburgh School of Medicine,Translational Neuroscience Program, University of Pittsburgh School of Medicine
| | | | - David A. Lewis
- Department of Neuroscience, University of Pittsburgh School of Medicine,Department of Psychiatry, University of Pittsburgh School of Medicine,Translational Neuroscience Program, University of Pittsburgh School of Medicine
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50
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Morse EM, Sun X, Olberding JR, Ha BH, Boggon TJ, Calderwood DA. PAK6 targets to cell-cell adhesions through its N-terminus in a Cdc42-dependent manner to drive epithelial colony escape. J Cell Sci 2015; 129:380-93. [PMID: 26598554 DOI: 10.1242/jcs.177493] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 11/18/2015] [Indexed: 12/26/2022] Open
Abstract
The six serine/threonine kinases in the p21-activated kinase (PAK) family are important regulators of cell adhesion, motility and survival. PAK6, which is overexpressed in prostate cancer, was recently reported to localize to cell-cell adhesions and to drive epithelial cell colony escape. Here we report that PAK6 targeting to cell-cell adhesions occurs through its N-terminus, requiring both its Cdc42/Rac interactive binding (CRIB) domain and an adjacent polybasic region for maximal targeting efficiency. We find PAK6 localization to cell-cell adhesions is Cdc42-dependent, as Cdc42 knockdown inhibits PAK6 targeting to cell-cell adhesions. We further find the ability of PAK6 to drive epithelial cell colony escape requires kinase activity and is disrupted by mutations that perturb PAK6 cell-cell adhesion targeting. Finally, we demonstrate that all type II PAKs (PAK4, PAK5 and PAK6) target to cell-cell adhesions, albeit to differing extents, but PAK1 (a type I PAK) does not. Notably, the ability of a PAK isoform to drive epithelial colony escape correlates with its targeting to cell-cell adhesions. We conclude that PAKs have a broader role in the regulation of cell-cell adhesions than previously appreciated.
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Affiliation(s)
- Elizabeth M Morse
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Xiaowen Sun
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Jordan R Olberding
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Byung Hak Ha
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Titus J Boggon
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06520, USA Yale Cancer Center, Yale University School of Medicine, New Haven, CT 06520, USA
| | - David A Calderwood
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA Yale Cancer Center, Yale University School of Medicine, New Haven, CT 06520, USA
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