1
|
Minegishi T, Kastian RF, Inagaki N. Mechanical regulation of synapse formation and plasticity. Semin Cell Dev Biol 2023; 140:82-89. [PMID: 35659473 DOI: 10.1016/j.semcdb.2022.05.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 05/10/2022] [Accepted: 05/17/2022] [Indexed: 01/28/2023]
Abstract
Dendritic spines are small protrusions arising from dendrites and constitute the major compartment of excitatory post-synapses. They change in number, shape, and size throughout life; these changes are thought to be associated with formation and reorganization of neuronal networks underlying learning and memory. As spines in the brain are surrounded by the microenvironment including neighboring cells and the extracellular matrix, their protrusion requires generation of force to push against these structures. In turn, neighboring cells receive force from protruding spines. Recent studies have identified BAR-domain proteins as being involved in membrane deformation to initiate spine formation. In addition, forces for dendritic filopodium extension and activity-induced spine expansion are generated through cooperation between actin polymerization and clutch coupling. On the other hand, force from expanding spines affects neurotransmitter release from presynaptic terminals. Here, we review recent advances in our understanding of the physical aspects of synapse formation and plasticity, mainly focusing on spine dynamics.
Collapse
Affiliation(s)
- Takunori Minegishi
- Laboratory of Systems Neurobiology and Medicine, Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
| | - Ria Fajarwati Kastian
- Laboratory of Systems Neurobiology and Medicine, Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan; Research Center for Genetic Engineering, National Research and Innovation Agency Republic of Indonesia, Cibinong, Bogor, Indonesia
| | - Naoyuki Inagaki
- Laboratory of Systems Neurobiology and Medicine, Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan.
| |
Collapse
|
2
|
Wan Mohamad Noor WNI, Nguyen NTH, Cheong TH, Chek MF, Hakoshima T, Inaba T, Hanawa-Suetsugu K, Nishimura T, Suetsugu S. Small GTPase Cdc42, WASP, and scaffold proteins for higher-order assembly of the F-BAR domain protein. SCIENCE ADVANCES 2023; 9:eadf5143. [PMID: 37126564 PMCID: PMC10132759 DOI: 10.1126/sciadv.adf5143] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The higher-order assembly of Bin-amphiphysin-Rvs (BAR) domain proteins, including the FCH-BAR (F-BAR) domain proteins, into lattice on the membrane is essential for the formation of subcellular structures. However, the regulation of their ordered assembly has not been elucidated. Here, we show that the higher ordered assembly of growth-arrested specific 7 (GAS7), an F-BAR domain protein, is regulated by the multivalent scaffold proteins of Wiskott-Aldrich syndrome protein (WASP)/neural WASP, that commonly binds to the BAR domain superfamily proteins, together with WISH, Nck, the activated small guanosine triphosphatase Cdc42, and a membrane-anchored phagocytic receptor. The assembly kinetics by fluorescence resonance energy transfer monitoring indicated that the GAS7 assembly on liposomes started within seconds and was further increased by the presence of these proteins. The regulated GAS7 assembly was abolished by Wiskott-Aldrich syndrome mutations both in vitro and in cellular phagocytosis. Therefore, Cdc42 and the scaffold proteins that commonly bind to the BAR domain superfamily proteins promoted GAS7 assembly.
Collapse
Affiliation(s)
- Wan Nurul Izzati Wan Mohamad Noor
- Division of Biological Science, Graduate school of Science and Technology, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara 630-0192, Japan
| | - Nhung Thi Hong Nguyen
- Division of Biological Science, Graduate school of Science and Technology, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara 630-0192, Japan
| | - Theng Ho Cheong
- Division of Biological Science, Graduate school of Science and Technology, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara 630-0192, Japan
| | - Min Fey Chek
- Division of Biological Science, Graduate school of Science and Technology, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara 630-0192, Japan
| | - Toshio Hakoshima
- Division of Biological Science, Graduate school of Science and Technology, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara 630-0192, Japan
| | - Takehiko Inaba
- Division of Biological Science, Graduate school of Science and Technology, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara 630-0192, Japan
| | - Kyoko Hanawa-Suetsugu
- Division of Biological Science, Graduate school of Science and Technology, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara 630-0192, Japan
| | - Tamako Nishimura
- Division of Biological Science, Graduate school of Science and Technology, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara 630-0192, Japan
| | - Shiro Suetsugu
- Division of Biological Science, Graduate school of Science and Technology, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara 630-0192, Japan
- Data Science Center, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara 630-0192, Japan
- Center for Digital Green-Innovation, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara 630-0192, Japan
| |
Collapse
|
3
|
Actin-Binding Proteins in Cardiac Hypertrophy. Cells 2022; 11:cells11223566. [PMID: 36428995 PMCID: PMC9688942 DOI: 10.3390/cells11223566] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 11/04/2022] [Accepted: 11/08/2022] [Indexed: 11/16/2022] Open
Abstract
The heart reacts to a large number of pathological stimuli through cardiac hypertrophy, which finally can lead to heart failure. However, the molecular mechanisms of cardiac hypertrophy remain elusive. Actin participates in the formation of highly differentiated myofibrils under the regulation of actin-binding proteins (ABPs), which provides a structural basis for the contractile function and morphological change in cardiomyocytes. Previous studies have shown that the functional abnormality of ABPs can contribute to cardiac hypertrophy. Here, we review the function of various actin-binding proteins associated with the development of cardiac hypertrophy, which provides more references for the prevention and treatment of cardiomyopathy.
Collapse
|
4
|
Pimm ML, Liu X, Tuli F, Heritz J, Lojko A, Henty-Ridilla JL. Visualizing molecules of functional human profilin. eLife 2022; 11:e76485. [PMID: 35666129 PMCID: PMC9249392 DOI: 10.7554/elife.76485] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 06/06/2022] [Indexed: 11/20/2022] Open
Abstract
Profilin-1 (PFN1) is a cytoskeletal protein that regulates the dynamics of actin and microtubule assembly. Thus, PFN1 is essential for the normal division, motility, and morphology of cells. Unfortunately, conventional fusion and direct labeling strategies compromise different facets of PFN1 function. As a consequence, the only methods used to determine known PFN1 functions have been indirect and often deduced in cell-free biochemical assays. We engineered and characterized two genetically encoded versions of tagged PFN1 that behave identical to each other and the tag-free protein. In biochemical assays purified proteins bind to phosphoinositide lipids, catalyze nucleotide exchange on actin monomers, stimulate formin-mediated actin filament assembly, and bound tubulin dimers (kD = 1.89 µM) to impact microtubule dynamics. In PFN1-deficient mammalian cells, Halo-PFN1 or mApple-PFN1 (mAp-PEN1) restored morphological and cytoskeletal functions. Titrations of self-labeling Halo-ligands were used to visualize molecules of PFN1. This approach combined with specific function-disrupting point-mutants (Y6D and R88E) revealed PFN1 bound to microtubules in live cells. Cells expressing the ALS-associated G118V disease variant did not associate with actin filaments or microtubules. Thus, these tagged PFN1s are reliable tools for studying the dynamic interactions of PFN1 with actin or microtubules in vitro as well as in important cell processes or disease-states.
Collapse
Affiliation(s)
- Morgan L Pimm
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical UniversitySyracuseUnited States
| | - Xinbei Liu
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical UniversitySyracuseUnited States
| | - Farzana Tuli
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical UniversitySyracuseUnited States
| | - Jennifer Heritz
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical UniversitySyracuseUnited States
| | - Ashley Lojko
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical UniversitySyracuseUnited States
| | - Jessica L Henty-Ridilla
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical UniversitySyracuseUnited States
- Department of Neuroscience and Physiology, SUNY Upstate Medical UniversitySyracuseUnited States
| |
Collapse
|
5
|
Wang Y, Lu Y, Wan R, Wang Y, Zhang C, Li M, Deng P, Cao L, Hu C. Profilin 1 Induces Tumor Metastasis by Promoting Microvesicle Secretion Through the ROCK 1/p-MLC Pathway in Non-Small Cell Lung Cancer. Front Pharmacol 2022; 13:890891. [PMID: 35586060 PMCID: PMC9108340 DOI: 10.3389/fphar.2022.890891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 04/12/2022] [Indexed: 11/13/2022] Open
Abstract
Profilin 1 (PFN1), an actin-binding protein, plays contrasting roles in the metastasis of several cancers; however, its role in non-small cell lung cancer (NSCLC) metastasis remains unclear. Here, PFN1 expression was upregulated in metastatic NSCLC tissues. PFN1 overexpression significantly promotes NSCLC metastasis in vitro and in vivo. Proteomics analysis revealed PFN1 involvment in microvesicles (MVs) secretion. In vitro experiments confirmed that PFN1 overexpression increased secretion of MVs. MVs are important mediators of metastasis. Here, we show an increased abundance of MVs in the sera of patients with metastatic NSCLC compared to that in the sera of patients with non-metastatic NSCLC. Both in vitro and in vivo experiments revealed that PFN1 could increase MV secretion, and MVs derived from PFN1-overexpressing cells markedly promoted NSCLC metastasis. We then elucidated the mechanisms underlying PFN1-mediated regulation of MVs and found that PFN1 could interact with ROCK1 and enhance its kinase activity to promote myosin light chain (MLC) phosphorylation for MV secretion. Inhibition of ROCK1 decreased MV secretion and partially reversed the PFN1-induced promotion of NSCLC metastasis. Collectively, these findings show that PFN1 regulates MV secretion to promote NSCLC metastasis. PFN1 and MVs represent potential predictors or therapeutic targets for NSCLC metastasis.
Collapse
Affiliation(s)
- Ya Wang
- Department of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, China
| | - Yichen Lu
- Department of Oncology, Hunan Provincial People’s Hospital/The First Affiliated Hospital of Hunan Normal University, Changsha, China
| | - Rongjun Wan
- Department of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, China
| | - Yang Wang
- Department of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, China
| | - Chunfang Zhang
- Department of Thoracic Surgery, Xiangya Hospital, Central South University, Changsha, China
| | - Min Li
- Department of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, China
| | - Pengbo Deng
- Department of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, China
| | - Liming Cao
- Department of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, China
| | - Chengping Hu
- Department of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, China
- *Correspondence: Chengping Hu,
| |
Collapse
|
6
|
Liu X, Pimm ML, Haarer B, Brawner AT, Henty-Ridilla JL. Biochemical characterization of actin assembly mechanisms with ALS-associated profilin variants. Eur J Cell Biol 2022; 101:151212. [PMID: 35248815 PMCID: PMC10163920 DOI: 10.1016/j.ejcb.2022.151212] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 02/23/2022] [Accepted: 02/25/2022] [Indexed: 12/26/2022] Open
Abstract
Eight separate mutations in the actin-binding protein profilin-1 have been identified as a rare cause of amyotrophic lateral sclerosis (ALS). Profilin is essential for many neuronal cell processes through its regulation of lipids, nuclear signals, and cytoskeletal dynamics, including actin filament assembly. Direct interactions between profilin and actin monomers inhibit actin filament polymerization. In contrast, profilin can also stimulate polymerization by simultaneously binding actin monomers and proline-rich tracts found in other proteins. Whether the ALS-associated mutations in profilin compromise these actin assembly functions is unclear. We performed a quantitative biochemical comparison of the direct and formin mediated impact for the eight ALS-associated profilin variants on actin assembly using classic protein-binding and single-filament microscopy assays. We determined that the binding constant of each profilin for actin monomers generally correlates with the actin nucleation strength associated with each ALS-related profilin. In the presence of formin, the A20T, R136W, Q139L, and C71G variants failed to activate the elongation phase of actin assembly. This diverse range of formin-activities is not fully explained through profilin-poly-L-proline (PLP) interactions, as all ALS-associated variants bind a formin-derived PLP peptide with similar affinities. However, chemical denaturation experiments suggest that the folding stability of these profilins impact some of these effects on actin assembly. Thus, changes in profilin protein stability and alterations in actin filament polymerization may both contribute to the profilin-mediated actin disruptions in ALS.
Collapse
Affiliation(s)
- Xinbei Liu
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Morgan L Pimm
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Brian Haarer
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Andrew T Brawner
- Department of Neuroscience & Physiology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Jessica L Henty-Ridilla
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Department of Neuroscience & Physiology, SUNY Upstate Medical University, Syracuse, NY 13210, USA.
| |
Collapse
|
7
|
Murk K, Ornaghi M, Schiweck J. Profilin Isoforms in Health and Disease - All the Same but Different. Front Cell Dev Biol 2021; 9:681122. [PMID: 34458253 PMCID: PMC8387879 DOI: 10.3389/fcell.2021.681122] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 07/12/2021] [Indexed: 12/11/2022] Open
Abstract
Profilins are small actin binding proteins, which are structurally conserved throughout evolution. They are probably best known to promote and direct actin polymerization. However, they also participate in numerous cell biological processes beyond the roles typically ascribed to the actin cytoskeleton. Moreover, most complex organisms express several profilin isoforms. Their cellular functions are far from being understood, whereas a growing number of publications indicate that profilin isoforms are involved in the pathogenesis of various diseases. In this review, we will provide an overview of the profilin family and "typical" profilin properties including the control of actin dynamics. We will then discuss the profilin isoforms of higher animals in detail. In terms of cellular functions, we will focus on the role of Profilin 1 (PFN1) and Profilin 2a (PFN2a), which are co-expressed in the central nervous system. Finally, we will discuss recent findings that link PFN1 and PFN2a to neurological diseases, such as amyotrophic lateral sclerosis (ALS), Fragile X syndrome (FXS), Huntington's disease and spinal muscular atrophy (SMA).
Collapse
Affiliation(s)
- Kai Murk
- Institute of Biochemistry, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Marta Ornaghi
- Institute of Biochemistry, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Juliane Schiweck
- Institute of Biochemistry, Charité Universitätsmedizin Berlin, Berlin, Germany
| |
Collapse
|
8
|
Luttman JH, Colemon A, Mayro B, Pendergast AM. Role of the ABL tyrosine kinases in the epithelial-mesenchymal transition and the metastatic cascade. Cell Commun Signal 2021; 19:59. [PMID: 34022881 PMCID: PMC8140471 DOI: 10.1186/s12964-021-00739-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 04/16/2021] [Indexed: 12/20/2022] Open
Abstract
The ABL kinases, ABL1 and ABL2, promote tumor progression and metastasis in various solid tumors. Recent reports have shown that ABL kinases have increased expression and/or activity in solid tumors and that ABL inactivation impairs metastasis. The therapeutic effects of ABL inactivation are due in part to ABL-dependent regulation of diverse cellular processes related to the epithelial to mesenchymal transition and subsequent steps in the metastatic cascade. ABL kinases target multiple signaling pathways required for promoting one or more steps in the metastatic cascade. These findings highlight the potential utility of specific ABL kinase inhibitors as a novel treatment paradigm for patients with advanced metastatic disease. Video abstract.
Collapse
Affiliation(s)
- Jillian Hattaway Luttman
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, 308 Research Drive, C-233A LSRC Bldg., P.O. Box 3813, Durham, NC 27710 USA
| | - Ashley Colemon
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, 308 Research Drive, C-233A LSRC Bldg., P.O. Box 3813, Durham, NC 27710 USA
| | - Benjamin Mayro
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, 308 Research Drive, C-233A LSRC Bldg., P.O. Box 3813, Durham, NC 27710 USA
| | - Ann Marie Pendergast
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, 308 Research Drive, C-233A LSRC Bldg., P.O. Box 3813, Durham, NC 27710 USA
| |
Collapse
|
9
|
Abstract
Dynamic remodeling of the actin cytoskeleton is an essential feature for virtually all actin-dependent cellular processes, including cell migration, cell cycle progression, chromatin remodeling and gene expression, and even the DNA damage response. An altered actin cytoskeleton is a structural hallmark associated with numerous pathologies ranging from cardiovascular diseases to immune disorders, neurological diseases and cancer. The actin cytoskeleton in cells is regulated through the orchestrated actions of a myriad of actin-binding proteins. In this Review, we provide a brief overview of the structure and functions of the actin-monomer-binding protein profilin-1 (Pfn1) and then discuss how dysregulated expression of Pfn1 contributes to diseases associated with the cardiovascular system.
Collapse
Affiliation(s)
| | - David Gau
- Bioengineering, University of Pittsburgh
| | - Partha Roy
- Bioengineering, University of Pittsburgh.,Pathology, University of Pittsburgh, 306 Center for Bioengineering, University of Pittsburgh, 300 Technology Drive, Pittsburgh, PA 15219, USA
| |
Collapse
|
10
|
Gul SI, Ayoub A, Ali SA, Hanook S, Baig DN. Profilin 3 genetic architecture in glioma formalin fixed paraffin embedded (FFPE) archive. Gene 2021; 787:145614. [PMID: 33775850 DOI: 10.1016/j.gene.2021.145614] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 02/11/2021] [Accepted: 03/23/2021] [Indexed: 12/15/2022]
Abstract
Pfn3 is an intron-less gene, encoding actin binding protein that affects structure of cytoskeleton. Although, Pfn3 is mentioned in Allen Brain Atlas and in adult and prenatal Human Brain Tissue Gene Expression Profiles dataset, however, no report on brain and/or brain tumor associated Pfn3 nucleotide sequences are available in the databases. Moreover, pfn3 and pfn4 are always considered as testicular specific genes. The current study explored transcriptional expression profile and genetic architecture of pfn3 in a cohort of fifty formalin fixed paraffin embedded (FFPE) human glioma archive tissues. Results of designed study highlighted the significant dysregulated transcriptional pattern of pfn3. Molecular similarity index indicated 97% in nucleotide and 93% homology in protein sequences (with clear differences in nine amino acid residues). Thus, molecular variations in the pfn3 may be corelated with the malignancy of brain tumors, as previously, pfn1 and pfn2 were reported as tumor suppressor genes in other types of cancer.
Collapse
Affiliation(s)
- Samar Ijaz Gul
- School of Life Sciences, Forman Christian College (A Chartered University), Lahore 54600, Pakistan
| | - Aqsa Ayoub
- School of Life Sciences, Forman Christian College (A Chartered University), Lahore 54600, Pakistan
| | - Syed Aoun Ali
- The Institute of Health and Biomedical Innovation, School of Clinical Sciences, Queensland University of Technology, Translational Research Institute, 37 Kent St, Woolloongabba, Brisbane, QLD 4102, Australia.
| | - Sharoon Hanook
- Department of Statistics, Forman Christian College (A Chartered University), Lahore 54600, Pakistan.
| | - Deeba Noreen Baig
- School of Life Sciences, Forman Christian College (A Chartered University), Lahore 54600, Pakistan.
| |
Collapse
|
11
|
Castellanos-Montiel MJ, Chaineau M, Durcan TM. The Neglected Genes of ALS: Cytoskeletal Dynamics Impact Synaptic Degeneration in ALS. Front Cell Neurosci 2020; 14:594975. [PMID: 33281562 PMCID: PMC7691654 DOI: 10.3389/fncel.2020.594975] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 10/21/2020] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that selectively affects motor neurons (MNs) of the cortex, brainstem, and spinal cord. Several genes have been linked to both familial (fALS) and sporadic (sALS) cases of ALS. Among all the ALS-related genes, a group of genes known to directly affect cytoskeletal dynamics (ALS2, DCTN1, PFN1, KIF5A, NF-L, NF-H, PRPH, SPAST, and TUBA4A) is of high importance for MN health and survival, considering that MNs are large polarized cells with axons that can reach up to 1 m in length. In particular, cytoskeletal dynamics facilitate the transport of organelles and molecules across the long axonal distances within the cell, playing a key role in synapse maintenance. The majority of ALS-related genes affecting cytoskeletal dynamics were identified within the past two decades, making it a new area to explore for ALS. The purpose of this review is to provide insights into ALS-associated cytoskeletal genes and outline how recent studies have pointed towards novel pathways that might be impacted in ALS. Further studies making use of extensive analysis models to look for true hits, the newest technologies such as CRIPSR/Cas9, human induced pluripotent stem cells (iPSCs) and axon sequencing, as well as the development of more transgenic animal models could potentially help to: differentiate the variants that truly act as a primary cause of the disease from the ones that act as risk factors or disease modifiers, identify potential interactions between two or more ALS-related genes in disease onset and progression and increase our understanding of the molecular mechanisms leading to cytoskeletal defects. Altogether, this information will give us a hint on the real contribution of the cytoskeletal ALS-related genes during this lethal disease.
Collapse
Affiliation(s)
| | - Mathilde Chaineau
- Early Drug Discovery Unit (EDDU), Montreal Neurological Institute-Hospital, McGill University, Montreal, QC, Canada
| | - Thomas M Durcan
- Early Drug Discovery Unit (EDDU), Montreal Neurological Institute-Hospital, McGill University, Montreal, QC, Canada
| |
Collapse
|
12
|
Pimm ML, Hotaling J, Henty-Ridilla JL. Profilin choreographs actin and microtubules in cells and cancer. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2020; 355:155-204. [PMID: 32859370 PMCID: PMC7461721 DOI: 10.1016/bs.ircmb.2020.05.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Actin and microtubules play essential roles in aberrant cell processes that define and converge in cancer including: signaling, morphology, motility, and division. Actin and microtubules do not directly interact, however shared regulators coordinate these polymers. While many of the individual proteins important for regulating and choreographing actin and microtubule behaviors have been identified, the way these molecules collaborate or fail in normal or disease contexts is not fully understood. Decades of research focus on Profilin as a signaling molecule, lipid-binding protein, and canonical regulator of actin assembly. Recent reports demonstrate that Profilin also regulates microtubule dynamics and polymerization. Thus, Profilin can coordinate both actin and microtubule polymer systems. Here we reconsider the biochemical and cellular roles for Profilin with a focus on the essential cytoskeletal-based cell processes that go awry in cancer. We also explore how the use of model organisms has helped to elucidate mechanisms that underlie the regulatory essence of Profilin in vivo and in the context of disease.
Collapse
Affiliation(s)
- Morgan L Pimm
- Department of Cell and Developmental Biology, State University of New York (SUNY) Upstate Medical University, Syracuse, NY, United States
| | - Jessica Hotaling
- Department of Cell and Developmental Biology, State University of New York (SUNY) Upstate Medical University, Syracuse, NY, United States
| | - Jessica L Henty-Ridilla
- Department of Cell and Developmental Biology, State University of New York (SUNY) Upstate Medical University, Syracuse, NY, United States; Department of Biochemistry and Molecular Biology, State University of New York (SUNY) Upstate Medical University, Syracuse, NY, United States.
| |
Collapse
|
13
|
Gau D, Vignaud L, Allen A, Guo Z, Sahel J, Boone D, Koes D, Guillonneau X, Roy P. Disruption of profilin1 function suppresses developmental and pathological retinal neovascularization. J Biol Chem 2020; 295:9618-9629. [PMID: 32444495 PMCID: PMC7363146 DOI: 10.1074/jbc.ra120.012613] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 05/20/2020] [Indexed: 12/18/2022] Open
Abstract
Angiogenesis-mediated neovascularization in the eye is usually associated with visual complications. Pathological angiogenesis is particularly prominent in the retina in the settings of proliferative diabetic retinopathy, in which it can lead to permanent loss of vision. In this study, by bioinformatics analyses, we provide evidence for elevated expression of actin-binding protein PFN1 (profilin1) in the retinal vascular endothelial cells (VECs) of individuals with proliferative diabetic retinopathy, findings further supported by gene expression analyses for PFN1 in experimentally induced abnormal retinal neovascularization in an oxygen-induced retinopathy murine model. We observed that in a conditional knockout mouse model, postnatal deletion of the Pfn1 gene in VECs leads to defects in tip cell activity (marked by impaired filopodial protrusions) and reduced vascular sprouting, resulting in hypovascularization during developmental angiogenesis in the retina. Consistent with these findings, an investigative small molecule compound targeting the PFN1-actin interaction reduced random motility, proliferation, and cord morphogenesis of retinal VECs in vitro and experimentally induced abnormal retinal neovascularization in vivo In summary, these findings provide the first direct in vivo evidence that PFN1 is required for formation of actin-based protrusive structures and developmental angiogenesis in the retina. The proof of concept of susceptibility of abnormal angiogenesis to small molecule intervention of PFN1-actin interaction reported here lays a conceptual foundation for targeting PFN1 as a possible strategy in angiogenesis-dependent retinal diseases.
Collapse
Affiliation(s)
- David Gau
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Lucile Vignaud
- Institut de la Vision, Sorbonne Université, INSERM, Paris, France
| | - Abigail Allen
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Zhijian Guo
- Department of Nephrology, Southern Medical University, Guangzhou, China
| | - Jose Sahel
- Institut de la Vision, Sorbonne Université, INSERM, Paris, France
- Department of Ophthalmology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - David Boone
- Department of Biomedical Informatics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - David Koes
- Department of Computational Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | | | - Partha Roy
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| |
Collapse
|
14
|
Gross N, Peñagaricano F, Khatib H. Integration of whole-genome DNA methylation data with RNA sequencing data to identify markers for bull fertility. Anim Genet 2020; 51:502-510. [PMID: 32323873 DOI: 10.1111/age.12941] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/25/2020] [Indexed: 02/06/2023]
Abstract
Predicting bull fertility prior to breeding is a current challenge for the dairy industry. The use of molecular biomarkers has been previously assessed. However, the integration of this information has not been performed to extract biologically relevant markers. The goal of this study was to integrate DNA methylation data with previously published RNA-sequencing results in order to identify candidate markers for sire fertility. A total of 1765 differentially methylated cytosines were found between high- and low-fertility sires. Ten genes associated with 11 differentially methylated cytosines were found in a previous study of gene expression between high- and low-fertility sires. Additionally, two of these genes code for proteins found exclusively in bull seminal plasma. Collectively, our results reveal 10 genes that could be used in the future as a panel for predicting bull fertility.
Collapse
Affiliation(s)
- Nicole Gross
- Department of Animal Sciences, University of Wisconsin, Madison, WI, 53706, USA
| | | | - Hasan Khatib
- Department of Animal Sciences, University of Wisconsin, Madison, WI, 53706, USA
| |
Collapse
|
15
|
Mir SS, Bhat HF, Bhat ZF. Dynamic actin remodeling in response to lysophosphatidic acid. J Biomol Struct Dyn 2020; 38:5253-5265. [PMID: 31920158 DOI: 10.1080/07391102.2019.1696230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Lysophosphatidic acid (LPA) is a multifunctional regulator of actin cytoskeleton that exerts a dramatic impact on the actin cytoskeleton to build a platform for diverse cellular processes including growth cone guidance, neurite retraction and cell motility. It has been implicated in the formation and dissociation of complexes between actin and actin binding proteins, supporting its role in actin remodeling. Several studies point towards its ability to facilitate formation of special cellular structures including focal adhesions and actin stress fibres by phosphoregulation of several actin associated proteins and their multiple regulatory kinases and phosphatases. In addition, multiple levels of crosstalk among the signaling cascades activated by LPA, affect actin cytoskeleton-mediated cell migration and chemotaxis which in turn play a crucial role in cancer metastasis. In the current review, we have attempted to highlight the role of LPA as an actin modulator which functions by controlling activities of specific cellular proteins that underlie mechanisms employed in cytoskeletal and pathophysiological events within the cell. Further studies on the actin affecting/remodeling activity of LPA in different cell types will no doubt throw up many surprises essential to gain a full understanding of its contribution in physiological processes as well as in diseases.Communicated by Ramaswamy H. Sarma.
Collapse
Affiliation(s)
- Saima S Mir
- Department of Biotechnology, University of Kashmir, Srinagar, Jammu And Kashmir, India.,Division of Animal Biotechnology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir (SKUAST-K), Srinagar, Jammu And Kashmir, India
| | - Hina F Bhat
- Division of Animal Biotechnology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir (SKUAST-K), Srinagar, Jammu And Kashmir, India
| | - Zuhaib F Bhat
- Department of Wine, Food & Molecular Biosciences, Lincoln University, Lincoln, New Zealand.,Division of Livestock Products and Technology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Jammu (SKUAST-J), R.S. Pora, Jammu And Kashmir, India
| |
Collapse
|
16
|
Wang QC, Wan X, Jia RX, Xu Y, Liu X, Zhang Y, Sun SC. Inhibition of N-WASP affects actin-mediated cytokinesis during porcine oocyte maturation. Theriogenology 2020; 144:132-138. [PMID: 31940504 DOI: 10.1016/j.theriogenology.2020.01.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 12/02/2019] [Accepted: 01/05/2020] [Indexed: 02/07/2023]
Abstract
N-WASP is the mammalian ortholog of WASP which is an actin nucleation promoting factor and has been reported to regulate actin nucleation and polymerization for multiple cell activities. However, the expression and functions of N-WASP in porcine oocytes are still unclear. In this study, we showed that N-WASP expressed at all stages during porcine oocyte maturation, and immunofluorescence staining indicated that N-WASP mainly accumulated at the cortex in different stages of meiosis. Inhibition of N-WASP activity by Wiskostatin significantly decreased the rate of first polar body extrusion and disturbed the cell cycle progression of porcine oocytes. Further analysis indicated that cortical actin distribution was interfered by N-WASP inhibition, and this might be through its regulatory roles on the expression and localization of ARP2, a key component of actin nucleator Arp2/3 complex. Moreover, the expression of N-WASP decreased after ROCK activity inhibition, indicating a ROCK-N-WASP-ARP2/3 pathway for actin assembly in porcine oocytes. Taken together, these results suggest that N-WASP is critical for the regulation of actin filaments for cytokinesis during porcine oocyte maturation.
Collapse
Affiliation(s)
- Qiao-Chu Wang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Xiang Wan
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Ru-Xia Jia
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yao Xu
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Xiuhong Liu
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yu Zhang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Shao-Chen Sun
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
| |
Collapse
|
17
|
Brettle M, Stefen H, Djordjevic A, Fok SYY, Chan JW, van Hummel A, van der Hoven J, Przybyla M, Volkerling A, Ke YD, Delerue F, Ittner LM, Fath T. Developmental Expression of Mutant PFN1 in Motor Neurons Impacts Neuronal Growth and Motor Performance of Young and Adult Mice. Front Mol Neurosci 2019; 12:231. [PMID: 31611772 PMCID: PMC6776973 DOI: 10.3389/fnmol.2019.00231] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 09/10/2019] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease with limited treatment and no cure. Mutations in profilin 1 were identified as a cause of familial ALS (fALS) in 2012. We investigated the functional impact of mutant profilin 1 expression in spinal cords during mouse development. We developed a novel mouse model with the expression of profilin 1 C71G under the control of the Hb9 promoter, targeting expression to α-motor neurons in the spinal cord during development. Embryos of transgenic mice showed evidence of a significant reduction of brachial nerve diameter and a loss of Mendelian inheritance. Despite the lack of transgene expression, adult mice presented with significant motor deficits. Transgenic mice had a significant reduction in the number of motor neurons in the spinal cord. Further analysis of these motor neurons in aged transgenic mice revealed reduced levels of TDP-43 and ChAT expression. Although profilin 1 C71G was only expressed during development, adult mice presented with some ALS-associated pathology and motor symptoms. This study highlights the effect of profilin 1 during neurodevelopment and the impact that this may have in later ALS.
Collapse
Affiliation(s)
- Merryn Brettle
- School of Medical Sciences, Faculty of Medicine, UNSW Sydney, Randwick, NSW, Australia.,Biomedical Imaging Facility, Mark Wainwright Analytical Centre, UNSW Sydney, Randwick, NSW, Australia
| | - Holly Stefen
- Dementia Research Centre and Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Aleksandra Djordjevic
- School of Medical Sciences, Faculty of Medicine, UNSW Sydney, Randwick, NSW, Australia
| | - Sandra Y Y Fok
- School of Medical Sciences, Faculty of Medicine, UNSW Sydney, Randwick, NSW, Australia.,Biomedical Imaging Facility, Mark Wainwright Analytical Centre, UNSW Sydney, Randwick, NSW, Australia
| | - Josephine W Chan
- School of Medical Sciences, Faculty of Medicine, UNSW Sydney, Randwick, NSW, Australia
| | - Annika van Hummel
- Dementia Research Centre and Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Julia van der Hoven
- Dementia Research Centre and Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Magdalena Przybyla
- Dementia Research Centre and Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Alexander Volkerling
- School of Medical Sciences, Faculty of Medicine, UNSW Sydney, Randwick, NSW, Australia
| | - Yazi D Ke
- Dementia Research Centre and Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Fabien Delerue
- Dementia Research Centre and Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Lars M Ittner
- Dementia Research Centre and Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Thomas Fath
- School of Medical Sciences, Faculty of Medicine, UNSW Sydney, Randwick, NSW, Australia.,Dementia Research Centre and Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| |
Collapse
|
18
|
Skruber K, Read TA, Vitriol EA. Reconsidering an active role for G-actin in cytoskeletal regulation. J Cell Sci 2018; 131:131/1/jcs203760. [PMID: 29321224 DOI: 10.1242/jcs.203760] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Globular (G)-actin, the actin monomer, assembles into polarized filaments that form networks that can provide structural support, generate force and organize the cell. Many of these structures are highly dynamic and to maintain them, the cell relies on a large reserve of monomers. Classically, the G-actin pool has been thought of as homogenous. However, recent work has shown that actin monomers can exist in distinct groups that can be targeted to specific networks, where they drive and modify filament assembly in ways that can have profound effects on cellular behavior. This Review focuses on the potential factors that could create functionally distinct pools of actin monomers in the cell, including differences between the actin isoforms and the regulation of G-actin by monomer binding proteins, such as profilin and thymosin β4. Owing to difficulties in studying and visualizing G-actin, our knowledge over the precise role that specific actin monomer pools play in regulating cellular actin dynamics remains incomplete. Here, we discuss some of these unanswered questions and also provide a summary of the methodologies currently available for the imaging of G-actin.
Collapse
Affiliation(s)
- Kristen Skruber
- Department of Anatomy and Cell Biology, University of Florida, Gainesville, FL 32610, USA
| | - Tracy-Ann Read
- Department of Anatomy and Cell Biology, University of Florida, Gainesville, FL 32610, USA
| | - Eric A Vitriol
- Department of Anatomy and Cell Biology, University of Florida, Gainesville, FL 32610, USA
| |
Collapse
|
19
|
Henty-Ridilla JL, Juanes MA, Goode BL. Profilin Directly Promotes Microtubule Growth through Residues Mutated in Amyotrophic Lateral Sclerosis. Curr Biol 2017; 27:3535-3543.e4. [PMID: 29129529 PMCID: PMC5772683 DOI: 10.1016/j.cub.2017.10.002] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 08/31/2017] [Accepted: 10/02/2017] [Indexed: 12/11/2022]
Abstract
Profilin is an abundant actin monomer-binding protein with critical actin regulatory roles in vivo [1, 2]. However, profilin also influences microtubule dynamics in cells, which may be mediated in part through its interactions with formins that in turn bind microtubules [3, 4]. Specific residues on human profilin-1 (PFN1) are mutated in patients with amyotrophic lateral sclerosis (ALS) [5, 6]. However, the observation that some ALS-linked PFN1 mutants fail to alter cellular actin organization or dynamics [5-8] or in vitro actin-monomer affinity [9] has been perplexing, given that profilin is best understood as an actin regulator. Here, we investigated direct effects of profilin on microtubule dynamics and whether ALS-linked mutations in PFN1 disrupt such functions. We found that human, fly, and yeast profilin homologs all directly enhance microtubule growth rate by several-fold in vitro. Microtubule stimulatory effects were unaffected by mutations in the canonical actin- or poly-proline-binding sites of profilin. Instead, microtubule activities depended on specific surface residues on profilin mutated in ALS patients. Furthermore, microtubule effects were attenuated by increasing concentrations of actin monomers, suggesting competition between actin and microtubules for binding profilin. Consistent with these biochemical observations, a 2-fold increase in the expression level of wild-type PFN1, but not the ALS-linked PFN1 mutants, increased microtubule growth rates in cells. Together, these results demonstrate that profilin directly enhances the growth rate of microtubules. They further suggest that ALS-linked mutations in PFN1 may perturb cellular microtubule dynamics and/or the coordination between the actin and microtubule cytoskeletons, leading to motor neuron degeneration.
Collapse
Affiliation(s)
| | - M Angeles Juanes
- Department of Biology, Brandeis University, 415 South Street, Waltham, MA 02454, USA
| | - Bruce L Goode
- Department of Biology, Brandeis University, 415 South Street, Waltham, MA 02454, USA.
| |
Collapse
|
20
|
Bieling P, Hansen SD, Akin O, Li TD, Hayden CC, Fletcher DA, Mullins RD. WH2 and proline-rich domains of WASP-family proteins collaborate to accelerate actin filament elongation. EMBO J 2017; 37:102-121. [PMID: 29141912 PMCID: PMC5753033 DOI: 10.15252/embj.201797039] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 09/19/2017] [Accepted: 09/20/2017] [Indexed: 02/04/2023] Open
Abstract
WASP‐family proteins are known to promote assembly of branched actin networks by stimulating the filament‐nucleating activity of the Arp2/3 complex. Here, we show that WASP‐family proteins also function as polymerases that accelerate elongation of uncapped actin filaments. When clustered on a surface, WASP‐family proteins can drive branched actin networks to grow much faster than they could by direct incorporation of soluble monomers. This polymerase activity arises from the coordinated action of two regulatory sequences: (i) a WASP homology 2 (WH2) domain that binds actin, and (ii) a proline‐rich sequence that binds profilin–actin complexes. In the absence of profilin, WH2 domains are sufficient to accelerate filament elongation, but in the presence of profilin, proline‐rich sequences are required to support polymerase activity by (i) bringing polymerization‐competent actin monomers in proximity to growing filament ends, and (ii) promoting shuttling of actin monomers from profilin–actin complexes onto nearby WH2 domains. Unoccupied WH2 domains transiently associate with free filament ends, preventing their growth and dynamically tethering the branched actin network to the WASP‐family proteins that create it. Collaboration between WH2 and proline‐rich sequences thus strikes a balance between filament growth and tethering. Our work expands the number of critical roles that WASP‐family proteins play in the assembly of branched actin networks to at least three: (i) promoting dendritic nucleation; (ii) linking actin networks to membranes; and (iii) accelerating filament elongation.
Collapse
Affiliation(s)
- Peter Bieling
- Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute, University of California, San Francisco, CA, USA .,Department of Bioengineering & Biophysics Program, University of California, Berkeley, CA, USA.,Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - Scott D Hansen
- Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute, University of California, San Francisco, CA, USA
| | - Orkun Akin
- Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute, University of California, San Francisco, CA, USA
| | - Tai-De Li
- Department of Bioengineering & Biophysics Program, University of California, Berkeley, CA, USA.,Chan Zuckerberg Biohub, San Francisco, CA, USA.,Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | | | - Daniel A Fletcher
- Department of Bioengineering & Biophysics Program, University of California, Berkeley, CA, USA .,Chan Zuckerberg Biohub, San Francisco, CA, USA.,Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - R Dyche Mullins
- Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute, University of California, San Francisco, CA, USA
| |
Collapse
|
21
|
Nejedla M, Sadi S, Sulimenko V, de Almeida FN, Blom H, Draber P, Aspenström P, Karlsson R. Profilin connects actin assembly with microtubule dynamics. Mol Biol Cell 2016; 27:2381-93. [PMID: 27307590 PMCID: PMC4966980 DOI: 10.1091/mbc.e15-11-0799] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 06/09/2016] [Indexed: 12/29/2022] Open
Abstract
Profilin is a well-known regulator of actin filament formation. It indirectly associates with microtubules and influences their growth rate. Formins are the linker molecules, and the turnover of the actin microfilament system balances profilin association with the microtubules. Profilin controls actin nucleation and assembly processes in eukaryotic cells. Actin nucleation and elongation promoting factors (NEPFs) such as Ena/VASP, formins, and WASP-family proteins recruit profilin:actin for filament formation. Some of these are found to be microtubule associated, making actin polymerization from microtubule-associated platforms possible. Microtubules are implicated in focal adhesion turnover, cell polarity establishment, and migration, illustrating the coupling between actin and microtubule systems. Here we demonstrate that profilin is functionally linked to microtubules with formins and point to formins as major mediators of this association. To reach this conclusion, we combined different fluorescence microscopy techniques, including superresolution microscopy, with siRNA modulation of profilin expression and drug treatments to interfere with actin dynamics. Our studies show that profilin dynamically associates with microtubules and this fraction of profilin contributes to balance actin assembly during homeostatic cell growth and affects microtubule dynamics. Hence profilin functions as a regulator of microtubule (+)-end turnover in addition to being an actin control element.
Collapse
Affiliation(s)
- Michaela Nejedla
- Department of Molecular Biosciences, Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Sara Sadi
- Department of Molecular Biosciences, Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Vadym Sulimenko
- Institute of Molecular Genetics, ASCR, 142 20 Prague 4, Czech Republic
| | | | - Hans Blom
- Science for Life Laboratory, SE-171 21 Solna, Sweden
| | - Pavel Draber
- Institute of Molecular Genetics, ASCR, 142 20 Prague 4, Czech Republic
| | - Pontus Aspenström
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Roger Karlsson
- Department of Molecular Biosciences, Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden
| |
Collapse
|
22
|
Gau D, Veon W, Zeng X, Yates N, Shroff SG, Koes DR, Roy P. Threonine 89 Is an Important Residue of Profilin-1 That Is Phosphorylatable by Protein Kinase A. PLoS One 2016; 11:e0156313. [PMID: 27228149 PMCID: PMC4882052 DOI: 10.1371/journal.pone.0156313] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 05/12/2016] [Indexed: 01/09/2023] Open
Abstract
Objective Dynamic regulation of actin cytoskeleton is at the heart of all actin-based cellular events. In this study, we sought to identify novel post-translational modifications of Profilin-1 (Pfn1), an important regulator of actin polymerization in cells. Methodology We performed in vitro protein kinase assay followed by mass-spectrometry to identify Protein Kinase A (PKA) phosphorylation sites of Pfn1. By two-dimensional gel electrophoresis (2D-GE) analysis, we further examined the changes in the isoelectric profile of ectopically expressed Pfn1 in HEK-293 cells in response to forskolin (FSK), an activator of cAMP/PKA pathway. Finally, we combined molecular dynamics simulations (MDS), GST pull-down assay and F-actin analyses of mammalian cells expressing site-specific phosphomimetic variants of Pfn1 to predict the potential consequences of phosphorylation of Pfn1. Results and Significance We identified several PKA phosphorylation sites of Pfn1 including Threonine 89 (T89), a novel site. Consistent with PKA’s ability to phosphorylate Pfn1 in vitro, FSK stimulation increased the pool of the most negatively charged form of Pfn1 in HEK-293 cells which can be attenuated by PKA inhibitor H89. MDS predicted that T89 phosphorylation destabilizes an intramolecular interaction of Pfn1, potentially increasing its affinity for actin. The T89D phosphomimetic mutation of Pfn1 elicits several changes that are hallmarks of proteins folded into alternative three-dimensional conformations including detergent insolubility, protein aggregation and accelerated proteolysis, suggesting that T89 is a structurally important residue of Pfn1. Expression of T89D-Pfn1 induces actin:T89D-Pfn1 co-clusters and dramatically reduces overall actin polymerization in cells, indicating an actin-sequestering action of T89D-Pfn1. Finally, rendering T89 non-phosphorylatable causes a positive charge shift in the isoelectric profile of Pfn1 in a 2D gel electrophoresis analysis of cell extracts, a finding that is consistent with phosphorylation of a certain pool of intracellular Pfn1 on the T89 residue. In summary, we propose that T89 phosphorylation could have major functional consequences on Pfn1. This study paves the way for further investigation of the potential role of Pfn1 phosphorylation in PKA-mediated regulation of actin-dependent biological processes.
Collapse
Affiliation(s)
- David Gau
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - William Veon
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Xuemei Zeng
- Biomedical Mass Spectrometry Center, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Nathan Yates
- Biomedical Mass Spectrometry Center, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Sanjeev G. Shroff
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - David R. Koes
- Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Partha Roy
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
| |
Collapse
|
23
|
Abstract
UNLABELLED The presence of Sonic Hedgehog (Shh) and its signaling components in the neurons of the hippocampus raises a question about what role the Shh signaling pathway may play in these neurons. We show here that activation of the Shh signaling pathway stimulates axon elongation in rat hippocampal neurons. This Shh-induced effect depends on the pathway transducer Smoothened (Smo) and the transcription factor Gli1. The axon itself does not respond directly to Shh; instead, the Shh signal transduction originates from the somatodendritic region of the neurons and occurs in neurons with and without detectable primary cilia. Upon Shh stimulation, Smo localization to dendrites increases significantly. Shh pathway activation results in increased levels of profilin1 (Pfn1), an actin-binding protein. Mutations in Pfn1's actin-binding sites or reduction of Pfn1 eliminate the Shh-induced axon elongation. These findings indicate that Shh can regulate axon growth, which may be critical for development of hippocampal neurons. SIGNIFICANCE STATEMENT Although numerous signaling mechanisms have been identified that act directly on axons to regulate their outgrowth, it is not known whether signals transduced in dendrites may also affect axon outgrowth. We describe here a transcellular signaling pathway in embryonic hippocampal neurons in which activation of Sonic Hedgehog (Shh) receptors in dendrites stimulates axon growth. The pathway involves the dendritic-membrane-associated Shh signal transducer Smoothened (Smo) and the transcription factor Gli, which induces the expression of the gene encoding the actin-binding protein profilin 1. Our findings suggest scenarios in which stimulation of Shh in dendrites results in accelerated outgrowth of the axon, which therefore reaches its presumptive postsynaptic target cell more quickly. By this mechanism, Shh may play critical roles in the development of hippocampal neuronal circuits.
Collapse
|
24
|
Bugalhão JN, Mota LJ, Franco IS. Identification of regions within the Legionella pneumophila VipA effector protein involved in actin binding and polymerization and in interference with eukaryotic organelle trafficking. Microbiologyopen 2015; 5:118-33. [PMID: 26626407 PMCID: PMC4767423 DOI: 10.1002/mbo3.316] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2015] [Revised: 10/20/2015] [Accepted: 10/22/2015] [Indexed: 02/02/2023] Open
Abstract
The Legionella pneumophila effector protein VipA is an actin nucleator that co‐localizes with actin filaments and early endosomes in infected macrophages and which interferes with organelle trafficking when expressed in yeast. To identify the regions of VipA involved in its subcellular localization and functions, we ectopically expressed specific VipA mutant proteins in eukaryotic cells. This indicated that the characteristic punctate distribution of VipA depends on its NH2‐terminal (amino acid residues 1–133) and central coiled‐coil (amino acid residues 133–206) regions, and suggested a role for the COOH‐terminal (amino acid residues 206–339) region in association with actin filaments and for the NH2‐terminal in co‐localization with early endosomes. Co‐immunoprecipitation and in vitro assays showed that the COOH‐terminal region of VipA is necessary and sufficient to mediate actin binding, and is essential but insufficient to induce microfilament formation. Assays in yeast revealed that the NH2 and the COOH‐terminal regions, and possibly an NPY motif within the NH2 region of VipA, are necessary for interference with organelle trafficking. Overall, this suggests that subversion of eukaryotic vesicular trafficking by VipA involves both its ability to associate with early endosomes via its NH2‐terminal region and its capacity to bind and polymerize actin through its COOH‐terminal region.
Collapse
Affiliation(s)
- Joana N Bugalhão
- UCIBIO, REQUIMTE, Faculdade de Ciências e Tecnologia, Departamento de Ciências da Vida, Universidade NOVA de Lisboa, Caparica, Portugal
| | - Luís Jaime Mota
- UCIBIO, REQUIMTE, Faculdade de Ciências e Tecnologia, Departamento de Ciências da Vida, Universidade NOVA de Lisboa, Caparica, Portugal.,Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Irina S Franco
- UCIBIO, REQUIMTE, Faculdade de Ciências e Tecnologia, Departamento de Ciências da Vida, Universidade NOVA de Lisboa, Caparica, Portugal.,Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| |
Collapse
|
25
|
Barbieri L, Luchinat E, Banci L. Protein interaction patterns in different cellular environments are revealed by in-cell NMR. Sci Rep 2015; 5:14456. [PMID: 26399546 PMCID: PMC4585868 DOI: 10.1038/srep14456] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 08/20/2015] [Indexed: 12/27/2022] Open
Abstract
In-cell NMR allows obtaining atomic-level information on biological macromolecules in their physiological environment. Soluble proteins may interact with the cellular environment in different ways: either specifically, with their functional partners, or non-specifically, with other cellular components. Such behaviour often causes the disappearance of the NMR signals. Here we show that by introducing mutations on the human protein profilin 1, used here as a test case, the in-cell NMR signals can be recovered. In human cells both specific and non-specific interactions are present, while in bacterial cells only the effect of non-specific interactions is observed. By comparing the NMR signal recovery pattern in human and bacterial cells, the relative contribution of each type of interaction can be assessed. This strategy allows detecting solution in-cell NMR spectra of soluble proteins without altering their fold, thus extending the applicability of in-cell NMR to a wider range of proteins.
Collapse
Affiliation(s)
- Letizia Barbieri
- Magnetic Resonance Center - CERM, University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Florence, Italy.,Giotto Biotech S.r.l., Via Madonna del Piano 6, 50019 Sesto Fiorentino, Florence, Italy
| | - Enrico Luchinat
- Magnetic Resonance Center - CERM, University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Florence, Italy.,Department of Biomedical, Clinical and Experimental Sciences, University of Florence, Viale Morgagni 50, 50134 Florence, Italy
| | - Lucia Banci
- Magnetic Resonance Center - CERM, University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Florence, Italy.,Department of Chemistry, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy
| |
Collapse
|
26
|
Zuo Z, Che X, Wang Y, Li B, Li J, Dai W, Lin CP, Huang C. High mobility group Box-1 inhibits cancer cell motility and metastasis by suppressing activation of transcription factor CREB and nWASP expression. Oncotarget 2015; 5:7458-70. [PMID: 25277185 PMCID: PMC4202136 DOI: 10.18632/oncotarget.2150] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The ability to metastasize is a hallmark of malignant tumors, and metastasis is the principal cause of death of cancer patients. The High Mobility Group Box-1 (HMGB1) is a multifunction protein that serves as both a chromatin protein and an extracellular signaling molecule. Our current study demonstrated a novel mechanism of HMGB1 in the regulation of cancer cell actin polymerization, cell skeleton formation, cancer cell motility and metastasis. We found that knockdown of HMGB1 in human lung cancer A549 cells significantly increased cell β-actin polymerization, cell skeleton formation, cancer cell migration and invasion in vitro, as well as metastasis in vivo. And this increase could be inhibited by treatment of HMGB1 knockdown cells with recombinant human HMGB1. Further studies discovered that HMGB1 suppressed phosphorylation, nuclear translocation, and activation of CREB, by inhibiting nuclear translocation of PKA catalytic subunit. This reduces nWASP mRNA transcription and expression, further impairing cancer cell motility. Our findings on the novel mechanism underlying the HMGB1 anti-metastatic effect on cancer provides significant insight into the understanding of the nature of HMGB1 in cancer invasion and metastasis, further serving as key information for utilization of HMGB1 and its regulated downstream components as new targets for cancer therapy.
Collapse
Affiliation(s)
- Zhenghong Zuo
- Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, NY. State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, China.+ Contributed equally to this work
| | - Xun Che
- Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, NY. Contributed equally to this work
| | - Yulei Wang
- Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, NY
| | - Bowen Li
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, China
| | - Jingxia Li
- Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, NY
| | - Wei Dai
- Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, NY
| | - Charles P Lin
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute-Frederick, Frederick, MD, USA
| | - Chuanshu Huang
- Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, NY
| |
Collapse
|
27
|
Boopathy S, Silvas TV, Tischbein M, Jansen S, Shandilya SM, Zitzewitz JA, Landers JE, Goode BL, Schiffer CA, Bosco DA. Structural basis for mutation-induced destabilization of profilin 1 in ALS. Proc Natl Acad Sci U S A 2015; 112:7984-9. [PMID: 26056300 PMCID: PMC4491777 DOI: 10.1073/pnas.1424108112] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Mutations in profilin 1 (PFN1) are associated with amyotrophic lateral sclerosis (ALS); however, the pathological mechanism of PFN1 in this fatal disease is unknown. We demonstrate that ALS-linked mutations severely destabilize the native conformation of PFN1 in vitro and cause accelerated turnover of the PFN1 protein in cells. This mutation-induced destabilization can account for the high propensity of ALS-linked variants to aggregate and also provides rationale for their reported loss-of-function phenotypes in cell-based assays. The source of this destabilization is illuminated by the X-ray crystal structures of several PFN1 proteins, revealing an expanded cavity near the protein core of the destabilized M114T variant. In contrast, the E117G mutation only modestly perturbs the structure and stability of PFN1, an observation that reconciles the occurrence of this mutation in the control population. These findings suggest that a destabilized form of PFN1 underlies PFN1-mediated ALS pathogenesis.
Collapse
Affiliation(s)
- Sivakumar Boopathy
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605
| | - Tania V Silvas
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605
| | - Maeve Tischbein
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605
| | - Silvia Jansen
- Department of Biology, Brandeis University, Waltham, MA 02453
| | - Shivender M Shandilya
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605
| | - Jill A Zitzewitz
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605
| | - John E Landers
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605
| | - Bruce L Goode
- Department of Biology, Brandeis University, Waltham, MA 02453
| | - Celia A Schiffer
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605
| | - Daryl A Bosco
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605; Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605;
| |
Collapse
|
28
|
RhoA/mDia-1/profilin-1 signaling targets microvascular endothelial dysfunction in diabetic retinopathy. Graefes Arch Clin Exp Ophthalmol 2015; 253:669-80. [PMID: 25791356 DOI: 10.1007/s00417-015-2985-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Revised: 02/21/2015] [Accepted: 03/02/2015] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Diabetic retinopathy (DR) is a major cause of blindness in the working-age populations of developed countries, and effective treatments and prevention measures have long been the foci of study. Patients with DR invariably demonstrate impairments of the retinal microvascular endothelium. Many observational and preclinical studies have shown that angiogenesis and apoptosis play crucial roles in the pathogenesis of DR. Increasing evidence suggests that in DR, the small guanosine-5'-triphosphate-binding protein RhoA activates its downstream targets mammalian Diaphanous homolog 1 (mDia-1) and profilin-1, thus affecting important cellular functions, including cell morphology, motility, secretion, proliferation, and gene expression. However, the specific underlying mechanism of disease remains unclear. CONCLUSION This review focuses on the RhoA/mDia-1/profilin-1 signaling pathway that specifically triggers endothelial dysfunction in diabetic patients. Recently, RhoA and profilin-1 signaling has attracted a great deal of attention in the context of diabetes-related research. However, the precise molecular mechanism by which the RhoA/mDia-1/profilin-1 pathway is involved in progression of microvascular endothelial dysfunction (MVED) during DR has not been determined. This review briefly describes each feature of the cascade before exploring the most recent findings on how the pathway may trigger endothelial dysfunction in DR. When the underlying mechanisms are understood, novel therapies seeking to restore the endothelial homeostasis comprised in DR will become possible.
Collapse
|
29
|
Megakaryocyte-specific Profilin1-deficiency alters microtubule stability and causes a Wiskott–Aldrich syndrome-like platelet defect. Nat Commun 2014; 5:4746. [DOI: 10.1038/ncomms5746] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 07/20/2014] [Indexed: 11/08/2022] Open
|
30
|
Profilin 1 associates with stress granules and ALS-linked mutations alter stress granule dynamics. J Neurosci 2014; 34:8083-97. [PMID: 24920614 DOI: 10.1523/jneurosci.0543-14.2014] [Citation(s) in RCA: 113] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Mutations in the PFN1 gene encoding profilin 1 are a rare cause of familial amyotrophic lateral sclerosis (ALS). Profilin 1 is a well studied actin-binding protein but how PFN1 mutations cause ALS is unknown. The budding yeast, Saccharomyces cerevisiae, has one PFN1 ortholog. We expressed the ALS-linked profilin 1 mutant proteins in yeast, demonstrating a loss of protein stability and failure to restore growth to profilin mutant cells, without exhibiting gain-of-function toxicity. This model provides for simple and rapid screening of novel ALS-linked PFN1 variants. To gain insight into potential novel roles for profilin 1, we performed an unbiased, genome-wide synthetic lethal screen with yeast cells lacking profilin (pfy1Δ). Unexpectedly, deletion of several stress granule and processing body genes, including pbp1Δ, were found to be synthetic lethal with pfy1Δ. Mutations in ATXN2, the human ortholog of PBP1, are a known ALS genetic risk factor and ataxin 2 is a stress granule component in mammalian cells. Given this genetic interaction and recent evidence linking stress granule dynamics to ALS pathogenesis, we hypothesized that profilin 1 might also associate with stress granules. Here we report that profilin 1 and related protein profilin 2 are novel stress granule-associated proteins in mouse primary cortical neurons and in human cell lines and that ALS-linked mutations in profilin 1 alter stress granule dynamics, providing further evidence for the potential role of stress granules in ALS pathogenesis.
Collapse
|
31
|
Lorente G, Syriani E, Morales M. Actin filaments at the leading edge of cancer cells are characterized by a high mobile fraction and turnover regulation by profilin I. PLoS One 2014; 9:e85817. [PMID: 24465723 PMCID: PMC3895011 DOI: 10.1371/journal.pone.0085817] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Accepted: 12/03/2013] [Indexed: 11/18/2022] Open
Abstract
Cellular motility is the basis for cancer cell invasion and metastasis. In the case of breast cancer, the most common type of cancer among women, metastasis represents the most devastating stage of the disease. The central role of cellular motility in cancer development emphasizes the importance of understanding the specific mechanisms involved in this process. In this context, tumor development and metastasis would be the consequence of a loss or defect of the mechanisms that control cytoskeletal remodeling. Profilin I belongs to a family of small actin binding proteins that are thought to assist in actin filament elongation at the leading edge of migrating cells. Traditionally, Profilin I has been considered to be an essential control element for actin polymerization and cell migration. Expression of Profilin I is down-regulated in breast and various other cancer cells. In MDA-MB-231 cells, a breast cancer cell line, further inhibition of Profilin I expression promotes hypermotility and metastatic spread, a finding that contrasts with the proposed role of Profilin in enhancing polymerization. In this report, we have taken advantage of the fluorescence recovery after photobleaching (FRAP) of GFP-actin to quantify and compare actin dynamics at the leading edge level in both cancer and non-cancer cell models. Our results suggest that (i) a high level of actin dynamics (i.e., a large mobile fraction of actin filaments and a fast turnover) is a common characteristic of some cancer cells; (ii) actin polymerization shows a high degree of independence from the presence of extracellular growth factors; and (iii) our results also corroborate the role of Profilin I in regulating actin polymerization, as raising the intracellular levels of Profilin I decreased the mobile fraction ratio of actin filaments and slowed their polymerization rate; furthermore, increased Profilin levels also led to reduced individual cell velocity and directionality.
Collapse
Affiliation(s)
- Gisela Lorente
- Neurophysiology Laboratory, Deptartment of Physiological Sciences I, School of Medicine, University of Barcelona, Barcelona, Spain
| | - Emilio Syriani
- Structural Synaptic Plasticity Lab, Department of Neurodegenerative Diseases, CIBIR Piqueras 98, Logroño, La Rioja, Spain
| | - Miguel Morales
- Structural Synaptic Plasticity Lab, Department of Neurodegenerative Diseases, CIBIR Piqueras 98, Logroño, La Rioja, Spain
- * E-mail:
| |
Collapse
|
32
|
Abstract
Clustered N-WASP binds directly to actin-filament barbed ends and can either slow individual filament growth or processively accelerate the assembly of bundled actin filaments. This novel Arp2/3-independent mechanism of N-WASP likely plays a role in invadopodia and podosome formation, in which both N-WASP and actin filaments are tightly clustered. Neuronal Wiskott–Aldrich syndrome protein (N-WASP)–activated actin polymerization drives extension of invadopodia and podosomes into the basement layer. In addition to activating Arp2/3, N-WASP binds actin-filament barbed ends, and both N-WASP and barbed ends are tightly clustered in these invasive structures. We use nanofibers coated with N-WASP WWCA domains as model cell surfaces and single-actin-filament imaging to determine how clustered N-WASP affects Arp2/3-independent barbed-end assembly. Individual barbed ends captured by WWCA domains grow at or below their diffusion-limited assembly rate. At high filament densities, however, overlapping filaments form buckles between their nanofiber tethers and myosin attachment points. These buckles grew ∼3.4-fold faster than the diffusion-limited rate of unattached barbed ends. N-WASP constructs with and without the native polyproline (PP) region show similar rate enhancements in the absence of profilin, but profilin slows barbed-end acceleration from constructs containing the PP region. Increasing Mg2+ to enhance filament bundling increases the frequency of filament buckle formation, consistent with a requirement of accelerated assembly on barbed-end bundling. We propose that this novel N-WASP assembly activity provides an Arp2/3-independent force that drives nascent filament bundles into the basement layer during cell invasion.
Collapse
Affiliation(s)
- Nimisha Khanduja
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061
| | | |
Collapse
|
33
|
Chen Y, Zheng ZZ, Huang R, Chen K, Song W, Zhao B, Chen X, Yang Y, Yuan L, Shang HF. PFN1 mutations are rare in Han Chinese populations with amyotrophic lateral sclerosis. Neurobiol Aging 2013; 34:1922.e1-5. [PMID: 23428184 DOI: 10.1016/j.neurobiolaging.2013.01.013] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 01/06/2013] [Accepted: 01/17/2013] [Indexed: 02/05/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with unknown pathophysiological mechanisms. Profilin 1 gene (PFN1) has been identified as a causative gene, which accounts for 1% to 2% of familial ALS. In this study, we investigated the mutation spectrum of PFN1 in Chinese patients with ALS. A total of 550 ALS patients (including 540 sporadic ALS [SALS] and 10 familial ALS) from the Department of Neurology, West China Hospital of Sichuan University, were recruited for the study. From the same region, 545 healthy control individuals (HC) were recruited as a control group. The encoding regions of the PFN1 gene were screened by direct sequencing. Novel candidate mutations or variations were confirmed by polymerase chain reaction-restriction fragment length polymorphism. A novel nonsynonymous p.R136W mutation was identified in an early-onset SALS female patient. A novel synonymous mutation p.L88L detected in a late-onset SALS female patient was considered nonpathogenic, as it was also detected in a control subject. No mutations were found in 10 familial ALS patients. Moreover, we found a significant difference in the genotype distribution of reported rs13204 (p.L112L) between SALS patients and HC (p = 0.0030). The frequency of minor allele 'T' of rs13204 in the SALS group was significantly lower than that in HC (p = 0.0040, OR = 0.7270, 95% CI = 0.5848-0.9039). Our results suggest that PFN1 mutation is an uncommon cause of ALS in the Han Chinese population. The SNP rs13204 of the PFN1 gene may have an important function in ALS development. The phenotype of ALS patients with mutantPFN1 gene varies among different genetic backgrounds.
Collapse
Affiliation(s)
- YongPing Chen
- Department of Neurology and State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, SiChuan University, Chengdu, Sichuan, China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Suetsugu S. Activation of nucleation promoting factors for directional actin filament elongation: allosteric regulation and multimerization on the membrane. Semin Cell Dev Biol 2013; 24:267-71. [PMID: 23380397 DOI: 10.1016/j.semcdb.2013.01.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2012] [Revised: 01/11/2013] [Accepted: 01/17/2013] [Indexed: 01/02/2023]
Abstract
Nucleation promoting factors (NPFs) activate the Arp2/3 complex to produce branched actin filaments. Branched actin filaments are observed in most organelles, and specific NPFs, such as WASP, N-WASP, WAVEs, WASH, and WHAMM, exist for each organelle. Interestingly, Arp2/3 and NPFs are both inactive by themselves, and thus require activation. The exposure of the Arp2/3 activating region, the VCA fragment, is recognized to be a key event in the activation of the NPFs. Together, small GTPase binding, phosphorylation, SH3 binding, and membrane binding promote VCA exposure synergistically. The increase in the local concentration of NPF by multimerization is thought to occur with the combination of such activators, to maximally activate the NPF and confine the region of actin polymerization. The mechanism of uni-directional filament extension beneath the membrane also is discussed.
Collapse
Affiliation(s)
- Shiro Suetsugu
- Laboratory of Membrane and Cytoskeleton Dynamics, Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan.
| |
Collapse
|
35
|
|
36
|
Grantham J, Lassing I, Karlsson R. Controlling the cortical actin motor. PROTOPLASMA 2012; 249:1001-1015. [PMID: 22526202 PMCID: PMC3459087 DOI: 10.1007/s00709-012-0403-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Accepted: 03/21/2012] [Indexed: 05/31/2023]
Abstract
Actin is the essential force-generating component of the microfilament system, which powers numerous motile processes in eukaryotic cells and undergoes dynamic remodeling in response to different internal and external signaling. The ability of actin to polymerize into asymmetric filaments is the inherent property behind the site-directed force-generating capacity that operates during various intracellular movements and in surface protrusions. Not surprisingly, a broad variety of signaling pathways and components are involved in controlling and coordinating the activities of the actin microfilament system in a myriad of different interactions. The characterization of these processes has stimulated cell biologists for decades and has, as a consequence, resulted in a huge body of data. The purpose here is to present a cellular perspective on recent advances in our understanding of the microfilament system with respect to actin polymerization, filament structure and specific folding requirements.
Collapse
Affiliation(s)
- Julie Grantham
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Ingrid Lassing
- Department of Cell Biology, Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Roger Karlsson
- Department of Cell Biology, Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden
| |
Collapse
|
37
|
Mutations in the profilin 1 gene cause familial amyotrophic lateral sclerosis. Nature 2012; 488:499-503. [PMID: 22801503 PMCID: PMC3575525 DOI: 10.1038/nature11280] [Citation(s) in RCA: 459] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Accepted: 05/31/2012] [Indexed: 12/12/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a late-onset neurodegenerative disorder resulting from motor neuron death. Approximately 10% of cases are familial (FALS), typically with a dominant inheritance mode. Despite numerous advances in recent years, nearly 50% of FALS cases have unknown genetic aetiology. Here we show that mutations within the profilin 1 (PFN1) gene can cause FALS. PFN1 is crucial for the conversion of monomeric (G)-actin to filamentous (F)-actin. Exome sequencing of two large ALS families showed different mutations within the PFN1 gene. Further sequence analysis identified 4 mutations in 7 out of 274 FALS cases. Cells expressing PFN1 mutants contain ubiquitinated, insoluble aggregates that in many cases contain the ALS-associated protein TDP-43. PFN1 mutants also display decreased bound actin levels and can inhibit axon outgrowth. Furthermore, primary motor neurons expressing mutant PFN1 display smaller growth cones with a reduced F/G-actin ratio. These observations further document that cytoskeletal pathway alterations contribute to ALS pathogenesis.
Collapse
|
38
|
Rust MB, Kullmann JA, Witke W. Role of the actin-binding protein profilin1 in radial migration and glial cell adhesion of granule neurons in the cerebellum. Cell Adh Migr 2012; 6:13-7. [PMID: 22647936 DOI: 10.4161/cam.19845] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Profilins are small G-actin-binding proteins essential for cytoskeletal dynamics. Of the four mammalian profilin isoforms, profilin1 shows a broad expression pattern, profilin2 is abundant in the brain, and profilin3 and profilin4 are restricted to the testis. In vitro studies on cancer and epithelial cell lines suggested a role for profilins in cell migration and cell-cell adhesion. Genetic studies in mice revealed the importance of profilin1 in neuronal migration, while profilin2 has apparently acquired a specific function in synaptic physiology. We recently reported a mouse mutant line lacking profilin1 in the brain; animals display morphological defects that are typical for impaired neuronal migration. We found that during cerebellar development, profilin1 is specifically required for radial migration and glial cell adhesion of granule neurons. Profilin1 mutants showed cerebellar hypoplasia and aberrant organization of cerebellar cortex layers, with ectopically arranged granule neurons. In this commentary, we briefly introduce the profilin family and summarize the current knowledge on profilin activity in cell migration and adhesion. Employing cerebellar granule cells as a model, we shed some light on the mechanisms by which profilin1 may control radial migration and glial cell adhesion. Finally, a potential implication of profilin1 in human developmental neuropathies is discussed.
Collapse
Affiliation(s)
- Marco B Rust
- Neurobiology/Neurophysiology Group, University of Kaiserslautern, Kaiserslautern, Germany.
| | | | | |
Collapse
|
39
|
Ding Z, Bae YH, Roy P. Molecular insights on context-specific role of profilin-1 in cell migration. Cell Adh Migr 2012; 6:442-9. [PMID: 23076048 DOI: 10.4161/cam.21832] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Profilin-1 (Pfn1) is a ubiquitously expressed actin-monomer binding protein that has been linked to many cellular activities ranging from control of actin polymerization to gene transcription. Traditionally, Pfn1 has been considered to be an essential control element for actin polymerization and cell migration. Seemingly contrasting this view, a few recent studies have shown evidence of an inhibitory action of Pfn1 on motility of certain types of carcinoma cells. In this review, we summarize biochemistry and functional aspects of Pfn1 in normal cells and bring in newly emerged action of Pfn1 in cancer cells that may explain its context-specific role in cell migration.
Collapse
Affiliation(s)
- Zhijie Ding
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
| | | | | |
Collapse
|
40
|
Penzes P, Cahill ME. Deconstructing signal transduction pathways that regulate the actin cytoskeleton in dendritic spines. Cytoskeleton (Hoboken) 2012; 69:426-41. [PMID: 22307832 DOI: 10.1002/cm.21015] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Revised: 01/29/2012] [Accepted: 01/30/2012] [Indexed: 11/10/2022]
Abstract
Dendritic spines are the sites of most excitatory synapses in the central nervous system. Recent studies have shown that spines function independently of each other, and they are currently the smallest known processing units in the brain. Spines exist in an array of morphologies, and spine structure helps dictate synaptic function. Dendritic spines are rich in actin, and actin rearrangements are critical regulators of spine morphology and density. In this review, we discuss the importance of actin in regulating dendritic spine morphogenesis, and discuss the upstream signal transduction pathways that either foster or inhibit actin polymerization. The understanding of actin regulatory pathways is best conceptualized as a hierarchical network in which molecules function in discrete levels defined by their molecular distance to actin. To this end, we focus on several classes of molecules, including guanine nucleotide exchange factors, small GTPases, small GTPase effectors, and actin binding proteins. We discuss how individual proteins in these molecular classes impact spine morphogenesis, and reveal the biochemical interactions in these networks that are responsible for shaping actin polymerization. Finally, we discuss the importance of these actin regulatory pathways in neuropsychiatric disorders.
Collapse
Affiliation(s)
- Peter Penzes
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
| | | |
Collapse
|
41
|
Abstract
beta-Actin mRNA is localized near the leading edge in several cell types where actin polymerization is actively promoting forward protrusion. The localization of the beta-actin mRNA near the leading edge is facilitated by a short sequence in the 3'UTR (untranslated region), the 'zipcode'. Localization of the mRNA at this region is important physiologically. Treatment of chicken embryo fibroblasts with antisense oligonucleotides complementary to the localization sequence (zipcode) in the 3'UTR leads to delocalization of beta-actin mRNA, alteration of cell phenotype and a decrease in cell motility. The dynamic image analysis system (DIAS) used to quantify movement of cells in the presence of sense and antisense oligonucleotides to the zipcode showed that net pathlength and average speed of antisense-treated cells were significantly lower than in sense-treated cells. This suggests that a decrease in persistence of direction of movement and not in velocity results from treatment of cells with zipcode-directed antisense oligonucleotides. We postulate that delocalization of beta-actin mRNA results in delocalization of nucleation sites and beta-actin protein from the leading edge followed by loss of cell polarity and directional movement. Hence the physiological consequences of beta-actin mRNA delocalization affect the stability of the cell phenotype.
Collapse
Affiliation(s)
- John Condeelis
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | | |
Collapse
|
42
|
FMRP regulates the transition from radial glial cells to intermediate progenitor cells during neocortical development. J Neurosci 2011; 31:1427-39. [PMID: 21273427 DOI: 10.1523/jneurosci.4854-10.2011] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
During vertebrate cortical neurogenesis, radial glial cells (RGCs) serve as neural stem cells that generate neurons directly or indirectly through intermediate progenitor cells (IPCs). The transition from RGCs to IPCs is a key step in determining overall neuronal production and may underlie evolutionary expansion of the cerebral cortex. Here we show that this transition is controlled by fragile X mental retardation protein (FMRP), an RNA-binding protein whose deficiency causes fragile X syndrome. Analysis of mouse embryos electroporated with FMRP small hairpin RNA and knock-out mouse embryos lacking FMRP reveals that specific loss of FMRP causes depletion of neocortical RGCs due to an RGC-to-IPC cell fate change. The RGC depletion is associated with altered F-actin organization and can be largely rescued by overexpressing profilin 1 (Pfn1), a core actin regulatory protein promoting F-actin formation. Our data suggest that FMRP suppresses the transition from RGCs to IPCs during neocortical development by an actin-dependent mechanism.
Collapse
|
43
|
Gau D, Ding Z, Baty C, Roy P. Fluorescence Resonance Energy Transfer (FRET)-based Detection of Profilin-VASP Interaction. Cell Mol Bioeng 2010; 4:1-8. [PMID: 21566724 DOI: 10.1007/s12195-010-0133-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Profilins belong to a family of small G-actin binding proteins which are thought to assist in F-actin elongation at the leading edge of migrating cells through their interactions with a host of actin-binding proteins including Ena (enabled)/VASP (vasodilator stimulated phosphoprotein). Profilin's interactions with the major actin regulators have been studied almost exclusively using biochemical methods. Therefore spatiotemporal features of these protein-protein interactions have not been resolved so far. In this paper, we for the first time demonstrate the feasibility of GFP-based fluorescence resonance energy transfer (FRET) technique to detect VASP's interaction with profilin-1, a ubiquitously expressed member of profilin family of genes. Specifically, we performed acceptor photobleaching FRET in MDA-MB-231 breast cancer cells to show prominent VASP-Pfn1 interaction at the membrane ruffles near the leading edge.
Collapse
Affiliation(s)
- Dave Gau
- Department of Bioengineering, University of Pittsburgh, 306 Center for Bioengineering, 300 Technology Drive, Pittsburgh, PA 15219, USA
| | | | | | | |
Collapse
|
44
|
Fukumi-Tominaga T, Mori Y, Matsuura A, Kaneko K, Matsui M, Ogata M, Tominaga M. DIP/WISH-deficient mice reveal Dia- and N-WASP-interacting protein as a regulator of cytoskeletal dynamics in embryonic fibroblasts. Genes Cells 2010; 14:1197-207. [PMID: 19778379 DOI: 10.1111/j.1365-2443.2009.01345.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
DIP/WISH binds to mammalian diaphanous and N-WASP, and functions as a scaffold protein by binding to Nck protein (called SPIN90). In addition, DIP/WISH accelerates actin polymerization through integration with N-WASP and is involved in cytoskeletal dynamics. We previously reported that DIP controls the activities of Rho GTPases in a Src-dependent manner, and accordingly contributes to cell motility (Meng et al. 2004). Here, we made the mice lacking DIP/WISH and demonstrated that DIP/WISH is critical for cell motility and adhesion by using murine embryonic fibroblasts (MEF). Rho activity was higher in DIP/WISH-deficient MEF cells even before platelet-derived growth factor (PDGF) or adhesion stimulation. Cell motility and adhesion were impaired in DIP/WISH-deficient MEF cells, and the MEF cells moved little probably due to the deficiency of tail retractions although they had many small membrane ruffles. Consistent with high Rho activity, DIP/WISH-deficient MEF cells exhibited many stress fibers due to clustering pre-existing actin filament. Thus, DIP/WISH is a negative regulator of Rho and modulates cell adhesion by controlling the integration of adhesion molecules.
Collapse
Affiliation(s)
- Tomoko Fukumi-Tominaga
- Section of Cell Signaling, Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Okazaki 444-8787, Japan.
| | | | | | | | | | | | | |
Collapse
|
45
|
Saarikangas J, Zhao H, Lappalainen P. Regulation of the actin cytoskeleton-plasma membrane interplay by phosphoinositides. Physiol Rev 2010; 90:259-89. [PMID: 20086078 DOI: 10.1152/physrev.00036.2009] [Citation(s) in RCA: 365] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The plasma membrane and the underlying cortical actin cytoskeleton undergo continuous dynamic interplay that is responsible for many essential aspects of cell physiology. Polymerization of actin filaments against cellular membranes provides the force for a number of cellular processes such as migration, morphogenesis, and endocytosis. Plasma membrane phosphoinositides (especially phosphatidylinositol bis- and trisphosphates) play a central role in regulating the organization and dynamics of the actin cytoskeleton by acting as platforms for protein recruitment, by triggering signaling cascades, and by directly regulating the activities of actin-binding proteins. Furthermore, a number of actin-associated proteins, such as BAR domain proteins, are capable of directly deforming phosphoinositide-rich membranes to induce plasma membrane protrusions or invaginations. Recent studies have also provided evidence that the actin cytoskeleton-plasma membrane interactions are misregulated in a number of pathological conditions such as cancer and during pathogen invasion. Here, we summarize the wealth of knowledge on how the cortical actin cytoskeleton is regulated by phosphoinositides during various cell biological processes. We also discuss the mechanisms by which interplay between actin dynamics and certain membrane deforming proteins regulate the morphology of the plasma membrane.
Collapse
Affiliation(s)
- Juha Saarikangas
- Program in Cell and Molecular Biology, Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | | | | |
Collapse
|
46
|
Ceriani M, Amigoni L, Scandiuzzi C, Berruti G, Martegani E. The PH-PxxP domain of RalGPS2 promotes PC12 cells differentiation acting as a dominant negative for RalA GTPase activation. Neurosci Res 2009; 66:290-8. [PMID: 20025911 DOI: 10.1016/j.neures.2009.11.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2009] [Revised: 11/11/2009] [Accepted: 11/30/2009] [Indexed: 10/20/2022]
Abstract
RalGPS2 is a guanine nucleotide exchange factor for RalA GTPase characterized by a C-terminal Pleckstrin Homology (PH) domain; this GEF is endogenously expressed in PC12 cells and in rat brain but its role in PC12 cells and in cell differentiation is actually unknown. Here we have shown that transient expression of RalGPS2-PH-PxxP domain in PC12 and PC12-TrkA cells induces high level of neurite outgrowth; this differentiation is comparable with that of PC12 cells treated with RalGPS2 siRNA. Stable PC12 cell lines expressing the PH-PxxP domain of RalGPS2 have been generated; in these cell lines the PH-PxxP domain acts as a dominant negative for RalA activation, promotes cells differentiation and re-directs NGF signals towards MAPKs. Furthermore it has been also demonstrated that the PH-PxxP domain of RalGPS2 induces microspikes formation a typical feature of cells in which the Cdc42 GTPase is constitutively activated.
Collapse
Affiliation(s)
- Michela Ceriani
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, Milan, Italy
| | | | | | | | | |
Collapse
|
47
|
Zhang J, Dong B, Siminovitch KA. Contributions of Wiskott-Aldrich syndrome family cytoskeletal regulatory adapters to immune regulation. Immunol Rev 2009; 232:175-94. [PMID: 19909364 DOI: 10.1111/j.1600-065x.2009.00846.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Cytoskeletal structure and dynamic rearrangement are integrally involved in coupling external stimuli to the orchestrated network of molecular interactions and cellular responses required for T-cell effector function. Members of the Wiskott-Aldrich syndrome protein (WASp) family are now widely recognized as cytoskeletal scaffolding adapters that coordinate the transmission of stimulatory signals to downstream induction of actin remodeling and cytoskeletal-dependent T-cell responses. In this review, we discuss the structural and functional properties of the WASp family members, with an emphasis on the roles of these proteins in the molecular pathways underpinning T-cell activation. The contributions of WASp family proteins and the cytoskeletal reorganization they evoke to expression of specific T-cell effector functions and the implications of such activity to normal immune responses and to the immunologic deficits manifested by Wiskott-Aldrich syndrome patients are also described.
Collapse
Affiliation(s)
- Jinyi Zhang
- Department of Medicine, University of Toronto, Mount Sinai Hospital Samuel Lunenfeld Research Institute, Toronto, ON, Canada
| | | | | |
Collapse
|
48
|
Yamada H, Padilla-Parra S, Park SJ, Itoh T, Chaineau M, Monaldi I, Cremona O, Benfenati F, De Camilli P, Coppey-Moisan M, Tramier M, Galli T, Takei K. Dynamic interaction of amphiphysin with N-WASP regulates actin assembly. J Biol Chem 2009; 284:34244-56. [PMID: 19759398 DOI: 10.1074/jbc.m109.064204] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Amphiphysin 1, an endocytic adaptor concentrated at synapses that couples clathrin-mediated endocytosis to dynamin-dependent fission, was also shown to have a regulatory role in actin dynamics. Here, we report that amphiphysin 1 interacts with N-WASP and stimulates N-WASP- and Arp2/3-dependent actin polymerization. Both the Src homology 3 and the N-BAR domains are required for this stimulation. Acidic liposome-triggered, N-WASP-dependent actin polymerization is strongly impaired in brain cytosol of amphiphysin 1 knock-out mice. FRET-FLIM analysis of Sertoli cells, where endogenously expressed amphiphysin 1 co-localizes with N-WASP in peripheral ruffles, confirmed the association between the two proteins in vivo. This association undergoes regulation and is enhanced by stimulating phosphatidylserine receptors on the cell surface with phosphatidylserine-containing liposomes that trigger ruffle formation. These results indicate that actin regulation is a key function of amphiphysin 1 and that such function cooperates with the endocytic adaptor role and membrane shaping/curvature sensing properties of the protein during the endocytic reaction.
Collapse
Affiliation(s)
- Hiroshi Yamada
- Department of Neuroscience, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
49
|
SMN, profilin IIa and plastin 3: A link between the deregulation of actin dynamics and SMA pathogenesis. Mol Cell Neurosci 2009; 42:66-74. [DOI: 10.1016/j.mcn.2009.05.009] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2009] [Revised: 05/20/2009] [Accepted: 05/26/2009] [Indexed: 11/21/2022] Open
|
50
|
Ding Z, Gau D, Deasy B, Wells A, Roy P. Both actin and polyproline interactions of profilin-1 are required for migration, invasion and capillary morphogenesis of vascular endothelial cells. Exp Cell Res 2009; 315:2963-73. [PMID: 19607826 DOI: 10.1016/j.yexcr.2009.07.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2009] [Revised: 07/07/2009] [Accepted: 07/07/2009] [Indexed: 11/15/2022]
Abstract
The objective of the present study was to evaluate how different ligand interactions of profilin-1 (Pfn1), an actin-binding protein that is upregulated during capillary morphogenesis of vascular endothelial cells (VEC), contribute to migration and capillary forming ability of VEC. We adopted a knockdown-knockin experimental system to stably express either fully functional form or mutants of Pfn1 that are impaired in binding to two of its major ligands, actin (H119E mutant) and proteins containing polyproline domains (H133S mutant), in a human dermal microvascular cell line (HmVEC) against near-null endogenous Pfn1 background. We found that silencing endogenous Pfn1 expression in HmVEC leads to slower random migration, reduced velocity of membrane protrusion and a significant impairment in matrigel-induced cord formation. Only re-expression of fully functional but not any of the two ligand-binding deficient mutants of Pfn1 rescues the above defects. We further show that loss of Pfn1 expression in VEC inhibits three-dimensional capillary morphogenesis, MMP2 secretion and ECM invasion. VEC invasion through ECM is also inhibited when actin and polyproline interactions of Pfn1 are disrupted. Together, these experimental data demonstrate that Pfn1 regulates VEC migration, invasion and capillary morphogenesis through its interaction with both actin and proline-rich ligands.
Collapse
Affiliation(s)
- Zhijie Ding
- Department of Bioengineering, University of Pittsburgh, PA, USA
| | | | | | | | | |
Collapse
|