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Pena E, San Martin-Salamanca R, El Alam S, Flores K, Arriaza K. Tau Protein Alterations Induced by Hypobaric Hypoxia Exposure. Int J Mol Sci 2024; 25:889. [PMID: 38255962 PMCID: PMC10815386 DOI: 10.3390/ijms25020889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 12/21/2023] [Accepted: 01/05/2024] [Indexed: 01/24/2024] Open
Abstract
Tauopathies are a group of neurodegenerative diseases whose central feature is dysfunction of the microtubule-associated protein tau (MAPT). Although the exact etiology of tauopathies is still unknown, it has been hypothesized that their onset may occur up to twenty years before the clear emergence of symptoms, which has led to questions about whether the prognosis of these diseases can be improved by, for instance, targeting the factors that influence tauopathy development. One such factor is hypoxia, which is strongly linked to Alzheimer's disease because of its association with obstructive sleep apnea and has been reported to affect molecular pathways related to the dysfunction and aggregation of tau proteins and other biomarkers of neurological damage. In particular, hypobaric hypoxia exposure increases the activation of several kinases related to the hyperphosphorylation of tau in neuronal cells, such as ERK, GSK3β, and CDK5. In addition, hypoxia also increases the levels of inflammatory molecules (IL-β1, IL-6, and TNF-α), which are also associated with neurodegeneration. This review discusses the many remaining questions regarding the influence of hypoxia on tauopathies and the contribution of high-altitude exposure to the development of these diseases.
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Affiliation(s)
| | | | - Samia El Alam
- High Altitude Medicine Research Center (CEIMA), Arturo Prat University, Iquique 1110939, Chile; (E.P.); (R.S.M.-S.); (K.F.); (K.A.)
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2
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Gilloteaux J, De Swert K, Suain V, Nicaise C. Thalamic Neuron Resilience during Osmotic Demyelination Syndrome (ODS) Is Revealed by Primary Cilium Outgrowth and ADP-ribosylation factor-like protein 13B Labeling in Axon Initial Segment. Int J Mol Sci 2023; 24:16448. [PMID: 38003639 PMCID: PMC10671465 DOI: 10.3390/ijms242216448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2023] [Revised: 11/10/2023] [Accepted: 11/13/2023] [Indexed: 11/26/2023] Open
Abstract
A murine osmotic demyelinating syndrome (ODS) model was developed through chronic hyponatremia, induced by desmopressin subcutaneous implants, followed by precipitous sodium restoration. The thalamic ventral posterolateral (VPL) and ventral posteromedial (VPM) relay nuclei were the most demyelinated regions where neuroglial damage could be evidenced without immune response. This report showed that following chronic hyponatremia, 12 h and 48 h time lapses after rebalancing osmolarity, amid the ODS-degraded outskirts, some resilient neuronal cell bodies built up primary cilium and axon hillock regions that extended into axon initial segments (AIS) where ADP-ribosylation factor-like protein 13B (ARL13B)-immunolabeled rod-like shape content was revealed. These AIS-labeled shaft lengths appeared proportional with the distance of neuronal cell bodies away from the ODS damaged epicenter and time lapses after correction of hyponatremia. Fine structure examination verified these neuron abundant transcriptions and translation regions marked by the ARL13B labeling associated with cell neurotubules and their complex cytoskeletal macromolecular architecture. This necessitated energetic transport to organize and restore those AIS away from the damaged ODS core demyelinated zone in the murine model. These labeled structures could substantiate how thalamic neuron resilience occurred as possible steps of a healing course out of ODS.
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Affiliation(s)
- Jacques Gilloteaux
- URPhyM, NARILIS, Université de Namur, Rue de Bruxelles 61, B-5000 Namur, Belgium; (J.G.); (K.D.S.)
- Department of Anatomical Sciences, St George’s University School of Medicine, Newcastle upon Tyne NE1 JG8, UK
| | - Kathleen De Swert
- URPhyM, NARILIS, Université de Namur, Rue de Bruxelles 61, B-5000 Namur, Belgium; (J.G.); (K.D.S.)
| | - Valérie Suain
- Laboratoire d’Histologie Générale, Université Libre de Bruxelles, Route de Lennik 808, B-1070 Bruxelles, Belgium;
| | - Charles Nicaise
- URPhyM, NARILIS, Université de Namur, Rue de Bruxelles 61, B-5000 Namur, Belgium; (J.G.); (K.D.S.)
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3
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CDK5/p35-Dependent Microtubule Reorganization Contributes to Homeostatic Shortening of the Axon Initial Segment. J Neurosci 2023; 43:359-372. [PMID: 36639893 PMCID: PMC9864565 DOI: 10.1523/jneurosci.0917-22.2022] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 10/13/2022] [Accepted: 10/18/2022] [Indexed: 12/12/2022] Open
Abstract
The structural plasticity of the axon initial segment (AIS) contributes to the homeostatic control of activity and optimizes the function of neural circuits; however, the underlying mechanisms are not fully understood. In this study, we prepared a slice culture containing nucleus magnocellularis from chickens of both sexes that reproduces most features of AIS plasticity in vivo, regarding its effects on characteristics of AIS and cell-type specificity, and revealed that microtubule reorganization via activation of CDK5 underlies plasticity. Treating the culture with a high-K+ medium shortened the AIS and reduced sodium current and membrane excitability, specifically in neurons tuned to high-frequency sound, creating a tonotopic difference in AIS length in the nucleus. Pharmacological analyses revealed that this AIS shortening was driven by multiple Ca2+ pathways and subsequent signaling molecules that converge on CDK5 via the activation of ERK1/2. AIS shortening was suppressed by overexpression of dominant-negative CDK5, whereas it was facilitated by the overexpression of p35, an activator of CDK5. Notably, p35(T138A), a phosphorylation-inactive mutant of p35, did not shorten the AIS. Moreover, microtubule stabilizers occluded AIS shortening during the p35 overexpression, indicating that CDK5/p35 mediated AIS shortening by promoting disassembly of microtubules at distal AIS. This study highlights the importance of microtubule reorganization and regulation of CDK5 activity in structural AIS plasticity and the tuning of AIS characteristics in neurons.SIGNIFICANCE STATEMENT The structural plasticity of AIS has a strong impact on the output of neurons and plays a fundamental role in the physiology and pathology of the brain. However, the mechanisms linking neuronal activity to structural changes in AIS are not well understood. In this study, we prepared an organotypic culture of avian auditory brainstem, reproducing most AIS plasticity features in vivo, and we revealed that activity-dependent AIS shortening occurs through the disassembly of microtubules at distal AIS via activation of CDK5/p35 signals. This study emphasizes the importance of microtubule reorganization and regulation of CDK5 activity in structural AIS plasticity and tonotopic differentiation of AIS structures in the brainstem auditory circuit.
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4
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Do PA, Lee CH. The Role of CDK5 in Tumours and Tumour Microenvironments. Cancers (Basel) 2020; 13:E101. [PMID: 33396266 PMCID: PMC7795262 DOI: 10.3390/cancers13010101] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 12/27/2020] [Accepted: 12/28/2020] [Indexed: 12/11/2022] Open
Abstract
Cyclin-dependent kinase 5 (CDK5), which belongs to the protein kinase family, regulates neuronal function but is also associated with cancer development and has been proposed as a target for cancer treatment. Indeed, CDK5 has roles in cell proliferation, apoptosis, angiogenesis, inflammation, and immune response. Aberrant CDK5 activation triggers tumour progression in numerous types of cancer. In this review, we summarise the role of CDK5 in cancer and neurons and CDK5 inhibitors. We expect that our review helps researchers to develop CDK5 inhibitors as treatments for refractory cancer.
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Affiliation(s)
| | - Chang Hoon Lee
- Phamaceutical Biochemistry, College of Pharmacy, BK21 FOUR Team, and Integrated Research Institute for Drug Development, Dongguk University, Goyang 100-715, Korea;
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5
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Posada-Duque RA, Cardona-Gómez GP. CDK5 Targeting as a Therapy for Recovering Neurovascular Unit Integrity in Alzheimer's Disease. J Alzheimers Dis 2020; 82:S141-S161. [PMID: 33016916 DOI: 10.3233/jad-200730] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The neurovascular unit (NVU) is responsible for synchronizing the energetic demand, vasodynamic changes, and neurochemical and electrical function of the brain through a closed and interdependent interaction of cell components conforming to brain tissue. In this review, we will focus on cyclin-dependent kinase 5 (CDK5) as a molecular pivot, which plays a crucial role in the healthy function of neurons, astrocytes, and the endothelium and is implicated in the cross-talk of cellular adhesion signaling, ion transmission, and cytoskeletal remodeling, thus allowing the individual and interconnected homeostasis of cerebral parenchyma. Then, we discuss how CDK5 overactivation affects the integrity of the NVU in Alzheimer's disease (AD) and cognitive impairment; we emphasize how CDK5 is involved in the excitotoxicity spreading of glutamate and Ca2+ imbalance under acute and chronic injury. Additionally, we present pharmacological and gene therapy strategies for producing partial depletion of CDK5 activity on neurons, astrocytes, or endothelium to recover neuroplasticity and neurotransmission, suggesting that the NVU should be the targeted tissue unit in protective strategies. Finally, we conclude that CDK5 could be effective due to its intervention on astrocytes by its end feet on the endothelium and neurons, acting as an intermediary cell between systemic and central communication in the brain. This review provides integrated guidance regarding the pathogenesis of and potential repair strategies for AD.
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Affiliation(s)
- Rafael Andrés Posada-Duque
- Cellular and Molecular Neurobiology Area, Group of Neuroscience of Antioquia, SIU, University of Antioquia, Medellín, Colombia.,Institute of Biology, Faculty of Exact and Natural Sciences, University of Antioquia, Medellín, Colombia
| | - Gloria Patricia Cardona-Gómez
- Cellular and Molecular Neurobiology Area, Group of Neuroscience of Antioquia, SIU, University of Antioquia, Medellín, Colombia
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6
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Au FK, Hau BK, Qi RZ. Nek2-mediated GAS2L1 phosphorylation and centrosome-linker disassembly induce centrosome disjunction. J Cell Biol 2020; 219:e201909094. [PMID: 32289147 PMCID: PMC7199859 DOI: 10.1083/jcb.201909094] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 01/16/2020] [Accepted: 02/28/2020] [Indexed: 12/13/2022] Open
Abstract
Centrosome disjunction occurs in late G2 to facilitate bipolar spindle formation and is mediated by the NIMA-related kinase Nek2. Here, we show that GAS2L1, a microtubule- and F-actin-binding protein required for centrosome disjunction, undergoes Nek2-mediated phosphorylation at Ser352 in G2/M. The phosphorylation is essential for centrosome disjunction in late G2 and for proper spindle assembly and faithful chromosome segregation in mitosis. GAS2L1 contains a calponin-homology (CH) domain and a GAS2-related (GAR) domain, which bind to F-actin and microtubules, respectively. Notably, the CH and GAR domains bind to each other to inhibit the functions of both domains, and Ser352 phosphorylation disrupts the interaction between the two domains and relieves the autoinhibition. We dissected the roles of the GAS2L1 phosphorylation and of centrosome-linker disassembly, which is another Nek2-mediated event, and found that these events together trigger centrosome disjunction. Therefore, our findings demonstrate the concerted Nek2 actions that split the centrosomes in late G2.
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Affiliation(s)
- Franco K.C. Au
- Division of Life Science and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China
- Shenzhen Key Laboratory of Edible and Medicinal Bioresources, HKUST Shenzhen Research Institute, Shenzhen, China
| | - Bill K.T. Hau
- Division of Life Science and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China
- Shenzhen Key Laboratory of Edible and Medicinal Bioresources, HKUST Shenzhen Research Institute, Shenzhen, China
| | - Robert Z. Qi
- Division of Life Science and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China
- Shenzhen Key Laboratory of Edible and Medicinal Bioresources, HKUST Shenzhen Research Institute, Shenzhen, China
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7
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Oner M, Lin E, Chen MC, Hsu FN, Shazzad Hossain Prince GM, Chiu KY, Teng CLJ, Yang TY, Wang HY, Yue CH, Yu CH, Lai CH, Hsieh JT, Lin H. Future Aspects of CDK5 in Prostate Cancer: From Pathogenesis to Therapeutic Implications. Int J Mol Sci 2019; 20:ijms20163881. [PMID: 31395805 PMCID: PMC6720211 DOI: 10.3390/ijms20163881] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Revised: 08/06/2019] [Accepted: 08/07/2019] [Indexed: 01/03/2023] Open
Abstract
Cyclin-dependent kinase 5 (CDK5) is a unique member of the cyclin-dependent kinase family. CDK5 is activated by binding with its regulatory proteins, mainly p35, and its activation is essential in the development of the central nervous system (CNS) and neurodegeneration. Recently, it has been reported that CDK5 plays important roles in regulating various biological and pathological processes, including cancer progression. Concerning prostate cancer, the androgen receptor (AR) is majorly involved in tumorigenesis, while CDK5 can phosphorylate AR and promotes the proliferation of prostate cancer cells. Clinical evidence has also shown that the level of CDK5 is associated with the progression of prostate cancer. Interestingly, inhibition of CDK5 prevents prostate cancer cell growth, while drug-triggered CDK5 hyperactivation leads to apoptosis. The blocking of CDK5 activity by its small interfering RNAs (siRNA) or Roscovitine, a pan-CDK inhibitor, reduces the cellular AR protein level and triggers the death of prostate cancer cells. Thus, CDK5 plays a crucial role in the growth of prostate cancer cells, and AR regulation is one of the important pathways. In this review paper, we summarize the significant studies on CDK5-mediated regulation of prostate cancer cells. We propose that the CDK5–p35 complex might be an outstanding candidate as a diagnostic marker and potential target for prostate cancer treatment in the near future.
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Affiliation(s)
- Muhammet Oner
- Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan
| | - Eugene Lin
- Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan
- Department of Urology, Chang Bing Show Chwan Memorial Hospital, Changhua 505, Taiwan
| | - Mei-Chih Chen
- Translational Cell Therapy Center, Department of Medical Research, China Medical University Hospital, Taichung 40447, Taiwan
| | - Fu-Ning Hsu
- Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan
| | | | - Kun-Yuan Chiu
- Division of Urology, Department of Surgery, Taichung Veterans General Hospital, Taichung 40705, Taiwan
| | - Chieh-Lin Jerry Teng
- Division of Hematology/Medical Oncology, Department of Internal, Medicine, Taichung Veterans General Hospital, Taichung 40705, Taiwan
| | - Tsung-Ying Yang
- Division of Chest Medicine, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung 40705, Taiwan
| | - Hsin-Yi Wang
- Department of Nuclear Medicine, Taichung Veterans General Hospital, Taichung 40705, Taiwan
| | - Chia-Herng Yue
- Department of Surgery, Tung's Taichung Metro Harbor Hospital, Taichung 435, Taiwan
| | - Ching-Han Yu
- Department of Physiology, School of Medicine, Chung Shan Medical University, Taichung 40201, Taiwan
| | - Chih-Ho Lai
- Department of Microbiology and Immunology, Chang Gung Medical University, Taoyuan 33302, Taiwan
| | - Jer-Tsong Hsieh
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Ho Lin
- Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan.
- Program in Translational Medicine and Rong Hsing Research Center for Translational Medicine, National Chung Hsing University, Taichung 40227, Taiwan.
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8
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Ferreras S, Fernández G, Danelon V, Pisano MV, Masseroni L, Chapleau CA, Krapacher FA, Mlewski EC, Mascó DH, Arias C, Pozzo-Miller L, Paglini MG. Cdk5 Is Essential for Amphetamine to Increase Dendritic Spine Density in Hippocampal Pyramidal Neurons. Front Cell Neurosci 2017; 11:372. [PMID: 29225566 PMCID: PMC5705944 DOI: 10.3389/fncel.2017.00372] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 11/08/2017] [Indexed: 12/12/2022] Open
Abstract
Psychostimulant drugs of abuse increase dendritic spine density in reward centers of the brain. However, little is known about their effects in the hippocampus, where activity-dependent changes in the density of dendritic spine are associated with learning and memory. Recent reports suggest that Cdk5 plays an important role in drug addiction, but its role in psychostimulant's effects on dendritic spines in hippocampus remain unknown. We used in vivo and in vitro approaches to demonstrate that amphetamine increases dendritic spine density in pyramidal neurons of the hippocampus. Primary cultures and organotypic slice cultures were used for cellular, molecular, pharmacological and biochemical analyses of the role of Cdk5/p25 in amphetamine-induced dendritic spine formation. Amphetamine (two-injection protocol) increased dendritic spine density in hippocampal neurons of thy1-green fluorescent protein (GFP) mice, as well as in hippocampal cultured neurons and organotypic slice cultures. Either genetic or pharmacological inhibition of Cdk5 activity prevented the amphetamine-induced increase in dendritic spine density. Amphetamine also increased spine density in neurons overexpressing the strong Cdk5 activator p25. Finally, inhibition of calpain, the protease necessary for the conversion of p35 to p25, prevented amphetamine's effect on dendritic spine density. We demonstrate, for the first time, that amphetamine increases the density of dendritic spine in hippocampal pyramidal neurons in vivo and in vitro. Moreover, we show that the Cdk5/p25 signaling and calpain activity are both necessary for the effect of amphetamine on dendritic spine density. The identification of molecular mechanisms underlying psychostimulant effects provides novel and promising therapeutic approaches for the treatment of drug addiction.
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Affiliation(s)
- Soledad Ferreras
- Laboratory of Neurophysiology, Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina.,Department of Neurobiology, Civitan International Research Center, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Guillermo Fernández
- Laboratory of Neurophysiology, Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Víctor Danelon
- Centro de Biología Celular y Molecular, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, IIBYT-CONICET, Córdoba, Argentina
| | - María V Pisano
- Laboratory of Neurophysiology, Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Luján Masseroni
- Laboratory of Neurobiology, Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Christopher A Chapleau
- Department of Neurobiology, Civitan International Research Center, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Favio A Krapacher
- Laboratory of Neurophysiology, Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Estela C Mlewski
- Laboratory of Neurophysiology, Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Daniel H Mascó
- Centro de Biología Celular y Molecular, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, IIBYT-CONICET, Córdoba, Argentina
| | - Carlos Arias
- Laboratory of Neurophysiology, Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Lucas Pozzo-Miller
- Department of Neurobiology, Civitan International Research Center, University of Alabama at Birmingham, Birmingham, AL, United States
| | - María G Paglini
- Laboratory of Neurophysiology, Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina.,Virology Institute "Dr. J. M. Vanella", Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina
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9
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Fong KW, Au FKC, Jia Y, Yang S, Zhou L, Qi RZ. Microtubule plus-end tracking of end-binding protein 1 (EB1) is regulated by CDK5 regulatory subunit-associated protein 2. J Biol Chem 2017; 292:7675-7687. [PMID: 28320860 DOI: 10.1074/jbc.m116.759746] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 03/15/2017] [Indexed: 01/08/2023] Open
Abstract
Microtubules are polar cytoskeleton filaments that extend via growth at their plus ends. Microtubule plus-end-tracking proteins (+TIPs) accumulate at these growing plus ends to control microtubule dynamics and attachment. The +TIP end-binding protein 1 (EB1) and its homologs possess an autonomous plus-end-tracking mechanism and interact with other known +TIPs, which then recruit those +TIPs to the growing plus ends. A major +TIP class contains the SXIP (Ser-X-Ile-Pro, with X denoting any amino acid residue) motif, known to interact with EB1 and its homologs for plus-end tracking, but the role of SXIP in regulating EB1 activities is unclear. We show here that an interaction of EB1 with the SXIP-containing +TIP CDK5 regulatory subunit-associated protein 2 (CDK5RAP2) regulates several EB1 activities, including microtubule plus-end tracking, dynamics at microtubule plus ends, microtubule and α/β-tubulin binding, and microtubule polymerization. The SXIP motif fused with a dimerization domain from CDK5RAP2 significantly enhanced EB1 plus-end-tracking and microtubule-polymerizing and bundling activities, but the SXIP motif alone failed to do so. An SXIP-binding-deficient EB1 mutant displayed significantly lower microtubule plus-end tracking than the wild-type protein in transfected cells. These results suggest that EB1 cooperates with CDK5RAP2 and perhaps other SXIP-containing +TIPs in tracking growing microtubule tips. We also generated plus-end-tracking chimeras of CDK5RAP2 and the adenomatous polyposis coli protein (APC) and found that overexpression of the dimerization domains interfered with microtubule plus-end tracking of their respective SXIP-containing chimeras. Our results suggest that disruption of SXIP dimerization enables detailed investigations of microtubule plus-end-associated functions of individual SXIP-containing +TIPs.
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Affiliation(s)
- Ka-Wing Fong
- From the Division of Life Science and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Franco K C Au
- From the Division of Life Science and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Yue Jia
- From the Division of Life Science and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Shaozhong Yang
- From the Division of Life Science and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Liying Zhou
- From the Division of Life Science and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Robert Z Qi
- From the Division of Life Science and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
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10
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Amin ND, Zheng Y, Bk B, Shukla V, Skuntz S, Grant P, Steiner J, Bhaskar M, Pant HC. The interaction of Munc 18 (p67) with the p10 domain of p35 protects in vivo Cdk5/p35 activity from inhibition by TFP5, a peptide derived from p35. Mol Biol Cell 2016; 27:3221-3232. [PMID: 27630261 PMCID: PMC5170856 DOI: 10.1091/mbc.e15-12-0857] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 09/07/2016] [Indexed: 11/11/2022] Open
Abstract
In a series of studies, we have identified TFP5, a truncated fragment of p35, the Cdk5 kinase regulatory protein, which inhibits Cdk5/p35 and the hyperactive Cdk5/p25 activities in test tube experiments. In cortical neurons, however, and in vivo in Alzheimer's disease (AD) model mice, the peptide specifically inhibits the Cdk5/p25 complex and not the endogenous Cdk5/p35. To account for the selective inhibition of Cdk5/p25 activity, we propose that the "p10" N-terminal domain of p35, absent in p25, spares Cdk5/p35 because p10 binds to macromolecules (e.g., tubulin and actin) as a membrane-bound multimeric complex that favors p35 binding to Cdk5 and catalysis. To test this hypothesis, we focused on Munc 18, a key synapse-associated neuronal protein, one of many proteins copurifying with Cdk5/p35 in membrane-bound multimeric complexes. Here we show that, in vitro, the addition of p67 protects Cdk5/p35 and has no effect on Cdk5/p25 activity in the presence of TFP5. In cortical neurons transfected with p67siRNA, we also show that TFP5 inhibits Cdk5/p35 activity, whereas in the presence of p67 the activity is protected. It does so without affecting any other kinases of the Cdk family of cyclin kinases. This difference may be of significant therapeutic value because the accumulation of the deregulated, hyperactive Cdk5/p25 complex in human brains has been implicated in pathology of AD and other neurodegenerative disorders.
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Affiliation(s)
- Niranjana D Amin
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
| | - Yali Zheng
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
| | - Binukumar Bk
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
| | - Varsha Shukla
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
| | - Susan Skuntz
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
| | - Philip Grant
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
| | - Joseph Steiner
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
| | - Manju Bhaskar
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
| | - Harish C Pant
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
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11
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The Activators of Cyclin-Dependent Kinase 5 p35 and p39 Are Essential for Oligodendrocyte Maturation, Process Formation, and Myelination. J Neurosci 2016; 36:3024-37. [PMID: 26961956 DOI: 10.1523/jneurosci.2250-15.2016] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The regulation of oligodendrocyte development and myelin formation in the CNS is poorly defined. Multiple signals influence the rate and extent of CNS myelination, including the noncanonical cyclin-dependent kinase 5 (Cdk5) whose functions are regulated by its activators p35 and p39. Here we show that selective loss of either p35 or p39 perturbed specific aspects of oligodendrocyte development, whereas loss of both p35 and p39 completely inhibited the development of mature oligodendrocytes and myelination. In the absence of p35, oligodendrocyte differentiation was delayed, process outgrowth was truncated in vitro, and the patterning and extent of myelination were perturbed in the CNS of p35(-/-) mice. In the absence of p39, oligodendrocyte maturation was transiently affected both in vitro and in vivo. However, loss of both p35 and p39 in oligodendrocyte lineage cells completely inhibited oligodendrocyte progenitor cell differentiation and myelination both in vitro and after transplantation into shiverer slice cultures. Loss of p35 and p39 had a more profound effect on oligodendrocyte development than simply the loss of Cdk5 and could not be rescued by Cdk5 overexpression. These data suggest p35 and p39 have specific and overlapping roles in oligodendrocyte development, some of which may be independent of Cdk5 activation.
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Shah K, Lahiri DK. A Tale of the Good and Bad: Remodeling of the Microtubule Network in the Brain by Cdk5. Mol Neurobiol 2016; 54:2255-2268. [PMID: 26944284 DOI: 10.1007/s12035-016-9792-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 02/11/2016] [Indexed: 10/22/2022]
Abstract
Cdk5, a cyclin-dependent kinase family member, is a global orchestrator of neuronal cytoskeletal dynamics. During embryogenesis, Cdk5 is indispensable for brain development. In adults, it is essential for numerous neuronal processes, including higher cognitive functions such as learning and memory formation, drug addiction, pain signaling, and long-term behavior changes through long-term potentiation and long-term depression, all of which rely on rapid alterations in the cytoskeleton. Cdk5 activity becomes deregulated in various brain disorders, including Alzheimer's disease, Parkinson's disease, Huntington's disease, attention-deficit hyperactivity disorder, epilepsy, schizophrenia, and ischemic stroke; these all result in profound remodeling of the neuronal cytoskeleton. This Commentary specifically focuses on the pleiotropic contribution of Cdk5 in regulating neuronal microtubule remodeling. Because the vast majority of the physiological substrates of Cdk5 are associated with the neuronal cytoskeleton, our emphasis is on the Cdk5 substrates, such as CRMP2, stathmin, drebrin, dixdc1, axin, MAP2, MAP1B, doublecortin, kinesin-5, and tau, that have allowed to unravel the molecular mechanisms through which Cdk5 exerts its divergent roles in regulating neuronal microtubule dynamics, both in healthy and disease states.
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Affiliation(s)
- Kavita Shah
- Department of Chemistry and Purdue University Center for Cancer Research, 560 Oval Drive, West Lafayette, IN, 47907, USA.
| | - Debomoy K Lahiri
- Departments of Psychiatry and Medical & Molecular Genetics, Institute of Psychiatric Research, Neuroscience Research Center, Indiana University School of Medicine, 320 W. 15th Street, Indianapolis, IN, 46202-2266, USA
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Posada-Duque RA, López-Tobón A, Piedrahita D, González-Billault C, Cardona-Gomez GP. p35 and Rac1 underlie the neuroprotection and cognitive improvement induced by CDK5 silencing. J Neurochem 2015; 134:354-70. [PMID: 25864429 DOI: 10.1111/jnc.13127] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 04/01/2015] [Accepted: 04/09/2015] [Indexed: 01/27/2023]
Abstract
CDK5 plays an important role in neurotransmission and synaptic plasticity in the normal function of the adult brain, and dysregulation can lead to Tau hyperphosphorylation and cognitive impairment. In a previous study, we demonstrated that RNAi knock down of CDK5 reduced the formation of neurofibrillary tangles (NFT) and prevented neuronal loss in triple transgenic Alzheimer's mice. Here, we report that CDK5 RNAi protected against glutamate-mediated excitotoxicity using primary hippocampal neurons transduced with adeno-associated virus 2.5 viral vector eGFP-tagged scrambled or CDK5 shRNA-miR during 12 days. Protection was dependent on a concomitant increase in p35 and was reversed using p35 RNAi, which affected the down-stream Rho GTPase activity. Furthermore, p35 over-expression and constitutively active Rac1 mimicked CDK5 silencing-induced neuroprotection. In addition, 3xTg-Alzheimer's disease mice (24 months old) were injected in the hippocampus with scrambled or CDK5 shRNA-miR, and spatial learning and memory were performed 3 weeks post-injection using 'Morris' water maze test. Our data showed that CDK5 knock down induced an increase in p35 protein levels and Rac activity in triple transgenic Alzheimer's mice, which correlated with the recovery of cognitive function; these findings confirm that increased p35 and active Rac are involved in neuroprotection. In summary, our data suggest that p35 acts as a mediator of Rho GTPase activity and contributes to the neuroprotection induced by CDK5 RNAi.
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Affiliation(s)
- Rafael Andres Posada-Duque
- Cellular and Molecular Neurobiology Area, Group of Neuroscience of Antioquia, Faculty of Medicine, SIU, Calle 70 N°. 52-21, University of Antioquia UdeA, Medellín, Colombia
| | - Alejandro López-Tobón
- Cellular and Molecular Neurobiology Area, Group of Neuroscience of Antioquia, Faculty of Medicine, SIU, Calle 70 N°. 52-21, University of Antioquia UdeA, Medellín, Colombia
| | - Diego Piedrahita
- Cellular and Molecular Neurobiology Area, Group of Neuroscience of Antioquia, Faculty of Medicine, SIU, Calle 70 N°. 52-21, University of Antioquia UdeA, Medellín, Colombia
| | - Christian González-Billault
- Department of Biology, Faculty of Sciences, Laboratory of Cell and Neuronal Dynamics, Universidad de Chile, Ñuñoa, Santiago, Chile
| | - Gloria Patricia Cardona-Gomez
- Cellular and Molecular Neurobiology Area, Group of Neuroscience of Antioquia, Faculty of Medicine, SIU, Calle 70 N°. 52-21, University of Antioquia UdeA, Medellín, Colombia
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Abstract
The small, calcium-sensor protein, calmodulin, is ubiquitously expressed and central to cell function in all cell types. Here the literature linking calmodulin to Alzheimer's disease is reviewed. Several experimentally-verified calmodulin-binding proteins are involved in the formation of amyloid-β plaques including amyloid-β protein precursor, β-secretase, presenilin-1, and ADAM10. Many others possess potential calmodulin-binding domains that remain to be verified. Three calmodulin binding proteins are associated with the formation of neurofibrillary tangles: two kinases (CaMKII, CDK5) and one protein phosphatase (PP2B or calcineurin). Many of the genes recently identified by genome wide association studies and other studies encode proteins that contain putative calmodulin-binding domains but only a couple (e.g., APOE, BIN1) have been experimentally confirmed as calmodulin binding proteins. At least two receptors involved in calcium metabolism and linked to Alzheimer's disease (mAchR; NMDAR) have also been identified as calmodulin-binding proteins. In addition to this, many proteins that are involved in other cellular events intimately associated with Alzheimer's disease including calcium channel function, cholesterol metabolism, neuroinflammation, endocytosis, cell cycle events, and apoptosis have been tentatively or experimentally verified as calmodulin binding proteins. The use of calmodulin as a potential biomarker and as a therapeutic target is discussed.
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Affiliation(s)
- Danton H. O’Day
- Department of Biology, University of Toronto at Mississauga, Mississauga, Ontario, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Kristeen Eshak
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Michael A. Myre
- Center for Human Genetic Research, Richard B. Simches Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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Microtubule-associated proteins in mesial temporal lobe epilepsy with and without psychiatric comorbidities and their relation with granular cell layer dispersion. BIOMED RESEARCH INTERNATIONAL 2013; 2013:960126. [PMID: 24069608 PMCID: PMC3771259 DOI: 10.1155/2013/960126] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 07/19/2013] [Accepted: 07/24/2013] [Indexed: 11/20/2022]
Abstract
Background. Despite strong association between epilepsy and psychiatric comorbidities, biological substrates are unknown. We have previously reported decreased mossy fiber sprouting in mesial temporal lobe epilepsy (MTLE) patients with psychosis and increased in those with major depression. Microtubule associated proteins (MAPs) are essentially involved in dendritic and synaptic sprouting. Methods. MTLE hippocampi of subjects without psychiatric history, MTLE + major depression, and MTLE + interictal psychosis derived from epilepsy surgery and control necropsies were investigated for neuronal density, granular layer dispersion, and MAP2 and tau immunohistochemistry. Results. Altered MAP2 and tau expression in MTLE and decreased tau expression in MTLE with psychosis were found. Granular layer dispersion correlated inversely with verbal memory scores, and with MAP2 and tau expression in the entorhinal cortex. Patients taking fluoxetine showed increased neuronal density in the granular layer and those taking haloperidol decreased neuronal density in CA3 and subiculum. Conclusions. Our results indicate relations between MAPs, granular layer dispersion, and memory that have not been previously investigated. Differential MAPs expression in human MTLE hippocampi with and without psychiatric comorbidities suggests that psychopathological states in MTLE rely on differential morphological and possibly neurochemical backgrounds. This clinical study was approved by our institution's Research Ethics Board (HC-FMRP no. 1270/2008) and is registered under the Brazilian National System of Information on Ethics in Human Research (SISNEP) no. 0423.0.004.000-07.
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Jia Y, Fong KW, Choi YK, See SS, Qi RZ. Dynamic recruitment of CDK5RAP2 to centrosomes requires its association with dynein. PLoS One 2013; 8:e68523. [PMID: 23874654 PMCID: PMC3714271 DOI: 10.1371/journal.pone.0068523] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Accepted: 05/30/2013] [Indexed: 12/05/2022] Open
Abstract
CDK5RAP2 is a centrosomal protein known to be involved in the regulation of the γ-tubulin ring complex and thus the organization of microtubule arrays. However, the mechanism by which CDK5RAP2 is itself recruited to centrosomes is poorly understood. We report here that CDK5RAP2 displays highly dynamic attachment to centrosomes in a microtubule-dependent manner. CDK5RAP2 associates with the retrograde transporter dynein-dynactin and contains a sequence motif that binds to dynein light chain 8. Significantly, disruption of cellular dynein-dynactin function reduces the centrosomal level of CDK5RAP2. These results reveal a key role of the dynein-dynactin complex in the dynamic recruitment of CDK5RAP2 to centrosomes.
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Affiliation(s)
- Yue Jia
- Division of Life Science and State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Ka-Wing Fong
- Division of Life Science and State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Yuk-Kwan Choi
- Division of Life Science and State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Siu-San See
- Division of Life Science and State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Robert Z. Qi
- Division of Life Science and State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
- * E-mail:
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Soluble alpha-APP (sAPPalpha) regulates CDK5 expression and activity in neurons. PLoS One 2013; 8:e65920. [PMID: 23776568 PMCID: PMC3679172 DOI: 10.1371/journal.pone.0065920] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 04/29/2013] [Indexed: 11/23/2022] Open
Abstract
A growing body of evidence suggests a role for soluble alpha-amyloid precursor protein (sAPPalpha) in pathomechanisms of Alzheimer disease (AD). This cleavage product of APP was identified to have neurotrophic properties. However, it remained enigmatic what proteins, targeted by sAPPalpha, might be involved in such neuroprotective actions. Here, we used high-resolution two-dimensional polyacrylamide gel electrophoresis to analyze proteome changes downstream of sAPPalpha in neurons. We present evidence that sAPPalpha regulates expression and activity of CDK5, a kinase that plays an important role in AD pathology. We also identified the cytoprotective chaperone ORP150 to be induced by sAPPalpha as part of this protective response. Finally, we present functional evidence that the sAPPalpha receptor SORLA is essential to mediate such molecular functions of sAPPalpha in neurons.
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Caspase-mediated cleavage of C53/LZAP protein causes abnormal microtubule bundling and rupture of the nuclear envelope. Cell Res 2013; 23:691-704. [PMID: 23478299 DOI: 10.1038/cr.2013.36] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Apoptotic nucleus undergoes distinct morphological and biochemical changes including nuclear shrinkage, chromatin condensation and DNA fragmentation, which are attributed to caspase-mediated cleavage of several nuclear substrates such as lamins. As most of active caspases reside in the cytoplasm, disruption of the nuclear-cytoplasmic barrier is essential for caspases to reach their nuclear targets. The prevailing proposed mechanism is that the increase in the permeability of nuclear pores induced by caspases allows the caspases and other apoptotic factors to diffuse into the nucleus, thereby resulting in the nuclear destruction. Here, we report a novel observation that physical rupture of the nuclear envelope (NE) occurs in the early stage of apoptosis. We found that the NE rupture was caused by caspase-mediated cleavage of C53/LZAP, a protein that has been implicated in various signaling pathways, including NF-κB signaling and DNA damage response, as well as tumorigenesis and metastasis. We also demonstrated that C53/LZAP bound indirectly to the microtubule (MT), and expression of the C53/LZAP cleavage product caused abnormal MT bundling and NE rupture. Taken together, our findings suggest a novel role of C53/LZAP in the regulation of MT dynamics and NE structure during apoptotic cell death. Our study may provide an additional mechanism for disruption of the nuclear-cytoplasmic barrier during apoptosis.
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Hashiguchi M, Hashiguchi T. Kinase–Kinase Interaction and Modulation of Tau Phosphorylation. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 300:121-60. [DOI: 10.1016/b978-0-12-405210-9.00004-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Cyclin-dependent kinase 5 regulates the polarized trafficking of neuropeptide-containing dense-core vesicles in Caenorhabditis elegans motor neurons. J Neurosci 2012; 32:8158-72. [PMID: 22699897 DOI: 10.1523/jneurosci.0251-12.2012] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The polarized trafficking of axonal and dendritic proteins is essential for the structure and function of neurons. Cyclin-dependent kinase 5 (CDK-5) and its activator CDKA-1/p35 regulate diverse aspects of nervous system development and function. Here, we show that CDK-5 and CDKA-1/p35 are required for the polarized distribution of neuropeptide-containing dense-core vesicles (DCVs) in Caenorhabditis elegans cholinergic motor neurons. In cdk-5 or cdka-1/p35 mutants, the predominantly axonal localization of DCVs containing INS-22 neuropeptides was disrupted and DCVs accumulated in dendrites. Time-lapse microscopy in DB class motor neurons revealed decreased trafficking of DCVs in axons and increased trafficking and accumulation of DCVs in cdk-5 mutant dendrites. The polarized distribution of several axonal and dendritic markers, including synaptic vesicles, was unaltered in cdk-5 mutant DB neurons. We found that microtubule polarity is plus-end out in axons and predominantly minus-end out in dendrites of DB neurons. Surprisingly, cdk-5 mutants had increased amounts of plus-end-out microtubules in dendrites, suggesting that CDK-5 regulates microtubule orientation. However, these changes in microtubule polarity are not responsible for the increased trafficking of DCVs into dendrites. Genetic analysis of cdk-5 and the plus-end-directed axonal DCV motor unc-104/KIF1A suggest that increased trafficking of UNC-104 into dendrites cannot explain the dendritic DCV accumulation. Instead, we found that mutations in the minus-end-directed motor cytoplasmic dynein, completely block the increased DCVs observed in cdk-5 mutant dendrites without affecting microtubule polarity. We propose a model in which CDK-5 regulates DCV polarity by both promoting DCV trafficking in axons and preventing dynein-dependent DCV trafficking into dendrites.
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Terabayashi T, Sakaguchi M, Shinmyozu K, Ohshima T, Johjima A, Ogura T, Miki H, Nishinakamura R. Phosphorylation of Kif26b promotes its polyubiquitination and subsequent proteasomal degradation during kidney development. PLoS One 2012; 7:e39714. [PMID: 22768111 PMCID: PMC3387196 DOI: 10.1371/journal.pone.0039714] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 05/25/2012] [Indexed: 01/24/2023] Open
Abstract
Kif26b, a member of the kinesin superfamily proteins (KIFs), is essential for kidney development. Kif26b expression is restricted to the metanephric mesenchyme, and its transcription is regulated by a zinc finger transcriptional regulator Sall1. However, the mechanism(s) by which Kif26b protein is regulated remain unknown. Here, we demonstrate phosphorylation and subsequent polyubiquitination of Kif26b in the developing kidney. We find that Kif26b interacts with an E3 ubiquitin ligase, neural precursor cell expressed developmentally down-regulated protein 4 (Nedd4) in developing kidney. Phosphorylation of Kif26b at Thr-1859 and Ser-1962 by the cyclin-dependent kinases (CDKs) enhances the interaction of Kif26b with Nedd4. Nedd4 polyubiquitinates Kif26b and thereby promotes degradation of Kif26b via the ubiquitin-proteasome pathway. Furthermore, Kif26b lacks ATPase activity but does associate with microtubules. Nocodazole treatment not only disrupts the localization of Kif26b to microtubules but also promotes phosphorylation and polyubiquitination of Kif26b. These results suggest that the function of Kif26b is microtubule-based and that Kif26b degradation in the metanephric mesenchyme via the ubiquitin-proteasome pathway may be important for proper kidney development.
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Affiliation(s)
- Takeshi Terabayashi
- Department of Kidney Development, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
- The Global COE “Cell Fate Regulation Research and Education Unit,” Kumamoto University, Honjo, Kumamoto, Japan
| | - Masaji Sakaguchi
- Department of Kidney Development, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
- The Global COE “Cell Fate Regulation Research and Education Unit,” Kumamoto University, Honjo, Kumamoto, Japan
| | - Kaori Shinmyozu
- Proteomics Laboratory, RIKEN Center for Developmental Biology, Kobe, Hyogo, Japan
| | - Toshio Ohshima
- Department of Life Science and Medical Bio-Science, Waseda University, Tokyo, Japan
| | - Ai Johjima
- The Global COE “Cell Fate Regulation Research and Education Unit,” Kumamoto University, Honjo, Kumamoto, Japan
- Department of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
| | - Teru Ogura
- The Global COE “Cell Fate Regulation Research and Education Unit,” Kumamoto University, Honjo, Kumamoto, Japan
- Department of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
| | - Hiroaki Miki
- Department of Cellular Regulation, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Ryuichi Nishinakamura
- Department of Kidney Development, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
- The Global COE “Cell Fate Regulation Research and Education Unit,” Kumamoto University, Honjo, Kumamoto, Japan
- * E-mail:
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McLinden KA, Trunova S, Giniger E. At the Fulcrum in Health and Disease: Cdk5 and the Balancing Acts of Neuronal Structure and Physiology. ACTA ACUST UNITED AC 2012; 2012:001. [PMID: 25364642 PMCID: PMC4212508 DOI: 10.4172/2168-975x.s1-001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cdk5 has been implicated in a multitude of processes in neuronal development, cell biology and physiology. These influence many neurological disorders, but the very breadth of Cdk5 effects has made it difficult to synthesize a coherent picture of the part played by this protein in health and disease. In this review, we focus on the roles of Cdk5 in neuronal function, particularly synaptic homeostasis, plasticity, neurotransmission, subcellular organization, and trafficking. We then discuss how disruption of these Cdk5 activities may initiate or exacerbate neural disorders. A recurring theme will be the sensitivity of Cdk5 sequelae to the precise biological context under consideration.
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Affiliation(s)
- Kristina A McLinden
- National Institute of Neurological Disorders and Stroke, USA ; National Human Genome Research Institute, USA
| | - Svetlana Trunova
- National Institute of Neurological Disorders and Stroke, USA ; National Human Genome Research Institute, USA
| | - Edward Giniger
- National Institute of Neurological Disorders and Stroke, USA ; National Human Genome Research Institute, USA
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Crews L, Ruf R, Patrick C, Dumaop W, Trejo-Morales M, Achim CL, Rockenstein E, Masliah E. Phosphorylation of collapsin response mediator protein-2 disrupts neuronal maturation in a model of adult neurogenesis: Implications for neurodegenerative disorders. Mol Neurodegener 2011; 6:67. [PMID: 21943307 PMCID: PMC3204248 DOI: 10.1186/1750-1326-6-67] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Accepted: 09/24/2011] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Recent studies suggest that the pathogenic process in neurodegenerative disorders may disrupt mature neuronal circuitries and neurogenesis in the adult brain. Abnormal activation of CDK5 is associated with neurodegenerative disorders, and recently a critical role for CDK5 in adult neurogenesis has been identified. We have developed an in vitro model of abnormal CDK5 activation during adult hippocampal neurogenesis, and here we used this model to investigate aberrantly phosphorylated downstream targets of CDK5. RESULTS Abnormal CDK5 activation in an in vitro model of adult neurogenesis results in hyperphosphorylation of collapsin-response mediator protein-2 (CRMP2) and impaired neurite outgrowth. Inhibition of CDK5, or expression of a non-phosphorylatable (S522A) CRMP2 construct reduced CRMP2 hyperphosphorylation, and reversed neurite outgrowth deficits. CRMP2 plays a role in microtubule dynamics; therefore we examined the integrity of microtubules in this model using biochemical and electron microscopy techniques. We found that microtubule organization was disrupted under conditions of CDK5 activation. Finally, to study the relevance of these findings to neurogenesis in neurodegenerative conditions associated with HIV infection, we performed immunochemical analyses of the brains of patients with HIV and transgenic mice expressing HIV-gp120 protein. CDK5-mediated CRMP2 phosphorylation was significantly increased in the hippocampus of patients with HIV encephalitis and in gp120 transgenic mice, and this effect was rescued by genetic down-modulation of CDK5 in the mouse model. CONCLUSIONS These results reveal a functional mechanism involving microtubule destabilization through which abnormal CDK5 activation and CRMP2 hyperphosphorylation might contribute to defective neurogenesis in neurodegenerative disorders such as HIV encephalitis.
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Affiliation(s)
- Leslie Crews
- Department of Neurosciences; University of California, San Diego; 9500 Gilman Drive, La Jolla, CA 92093-0624, USA.
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He L, Zhang Z, Yu Y, Ahmed S, Cheung NS, Qi RZ. The neuronal p35 activator of Cdk5 is a novel F-actin binding and bundling protein. Cell Mol Life Sci 2011; 68:1633-43. [PMID: 20976519 PMCID: PMC11114985 DOI: 10.1007/s00018-010-0562-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Revised: 09/24/2010] [Accepted: 10/05/2010] [Indexed: 12/11/2022]
Abstract
The neuronal Cdk5 activator p35 is involved in a multitude of neuronal activities, including cytoskeletal organization. We show here that p35 directly interacts with filamentous actin (F-actin) but not with monomeric actin (G-actin). Through binding, p35 induces the formation of actin bundles and stabilizes F-actin against dilution-induced depolymerization. p35 forms intermolecular self-associations, suggesting that p35 cross-links actin filaments into bundles via its intermolecular self-association. p35 dimerization and association with F-actin occur at the N-terminal region that is absent in the calpain-cleaved product p25, indicating that such p35 properties are lost by its truncation induced under neurotoxic conditions. Using p35 phosphorylated by Cdk5 and a mutational approach, we demonstrate that the phosphorylation of p35 promotes its homodimerization and p35-induced formation of F-actin bundles. In addition, the phosphorylation regulates p35 distribution to microtubule and actin cytoskeletons. Together, these observations define a novel function for p35 in cytoskeletal regulation.
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Affiliation(s)
- Lisheng He
- Department of Biochemistry, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong China
| | - Zhaojun Zhang
- Department of Biochemistry, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong China
| | - Yan Yu
- Department of Biochemistry, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong China
| | - Sohail Ahmed
- Institute of Medical Biology, 8A Biomedical Grove, #06-06, Immunos, Singapore, 138648 Republic of Singapore
| | - Nam Sang Cheung
- Menzies Research Institute, University of Tasmania, Hobart, TAS Australia
| | - Robert Z. Qi
- Department of Biochemistry, State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong China
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Xu J, Tsutsumi K, Tokuraku K, Estes KA, Hisanaga SI, Ikezu T. Actin interaction and regulation of cyclin-dependent kinase 5/p35 complex activity. J Neurochem 2011; 116:192-204. [PMID: 20492361 DOI: 10.1111/j.1471-4159.2010.06824.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Cyclin-dependent kinase 5 (Cdk5) plays a critical role during neurodevelopment, synaptic plasticity, and neurodegeneration. Cdk5 activity depends on association with neuronal proteins p35 and p25, a proteolytic product of p35. Cdk5 regulates the actin cytoskeletal dynamics that are essential for neuronal migration, neuritic growth, and synaptogenesis. However, little is known about the interaction of actin and Cdk5 and its effect on neuronal Cdk5 activity. In a previous study, we observed that Cdk5/p35 activity is negatively correlated with co-immunoprecipitated F-actin (filamentous actin) amounts in the mouse brain, and suggested that F-actin inhibits the formation of the Cdk5/p35 complex [Journal of Neuroscience (2008) vol. 28, p. 14511]. The experiments reported here were undertaken to elucidate the relationship between actin and the formation of the Cdk5/p35 complex and its activity. Instead of an F-actin-mediated inhibition, we propose that G-actin (globular actin) in the F-actin preparations is responsible for inhibiting Cdk5/p35 and Cdk5/p25 kinase activity. We found that F-actin binds to p35 but not p25 or Cdk5. We have shown that G-actin binds directly to Cdk5 without disrupting the formation of the Cdk5/p35 or Cdk5/p25 complexes. G-actin potently suppressed Cdk5/p35 and Cdk5/p25 activity when either histone H1 or purified human tau protein were used as substrates, indicating a substrate-independent inhibitory effect of G-actin on Cdk5 activity. Finally, G-actin suppressed the activity of Cdk5 immunoprecipitated from wild type and p35-deficient mouse brain, suggesting that G-actin suppresses endogenous Cdk5 activity in a p35-independent manner. Together, these results suggest a novel mechanism of actin cytoskeletal regulation of Cdk5/p35 activity.
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Affiliation(s)
- Jiqing Xu
- Center for Neurodegenerative Disorders, Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, USA
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Choi YK, Liu P, Sze SK, Dai C, Qi RZ. CDK5RAP2 stimulates microtubule nucleation by the gamma-tubulin ring complex. ACTA ACUST UNITED AC 2010; 191:1089-95. [PMID: 21135143 PMCID: PMC3002024 DOI: 10.1083/jcb.201007030] [Citation(s) in RCA: 206] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
CDK5RAP2 is a human microcephaly protein that contains a γ-tubulin complex (γ-TuC)-binding domain conserved in Drosophila melanogaster centrosomin and Schizosaccharomyces pombe Mto1p and Pcp1p, which are γ-TuC-tethering proteins. In this study, we show that this domain within CDK5RAP2 associates with the γ-tubulin ring complex (γ-TuRC) to stimulate its microtubule-nucleating activity and is therefore referred to as the γ-TuRC-mediated nucleation activator (γ-TuNA). γ-TuNA but not its γ-TuC-binding-deficient mutant stimulates microtubule nucleation by purified γ-TuRC in vitro and induces extensive, γ-TuRC-dependent nucleation of microtubules in a microtubule regrowth assay. γ-TuRC bound to γ-TuNA contains NME7, FAM128A/B, and actin in addition to γ-tubulin and GCP2-6. RNA interference-mediated depletion of CDK5RAP2 impairs both centrosomal and acentrosomal microtubule nucleation, although γ-TuRC assembly is unaffected. Collectively, these results suggest that the γ-TuNA found in CDK5RAP2 has regulatory functions in γ-TuRC-mediated microtubule nucleation.
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Affiliation(s)
- Yuk-Kwan Choi
- Department of Biochemistry, Hong Kong University of Science and Technology, Hong Kong, China
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27
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Zheng YL, Amin ND, Hu YF, Rudrabhatla P, Shukla V, Kanungo J, Kesavapany S, Grant P, Albers W, Pant HC. A 24-residue peptide (p5), derived from p35, the Cdk5 neuronal activator, specifically inhibits Cdk5-p25 hyperactivity and tau hyperphosphorylation. J Biol Chem 2010; 285:34202-12. [PMID: 20720012 DOI: 10.1074/jbc.m110.134643] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The activity of Cdk5-p35 is tightly regulated in the developing and mature nervous system. Stress-induced cleavage of the activator p35 to p25 and a p10 N-terminal domain induces deregulated Cdk5 hyperactivity and perikaryal aggregations of hyperphosphorylated Tau and neurofilaments, pathogenic hallmarks in neurodegenerative diseases, such as Alzheimer disease and amyotrophic lateral sclerosis, respectively. Previously, we identified a 125-residue truncated fragment of p35 called CIP that effectively and specifically inhibited Cdk5-p25 activity and Tau hyperphosphorylation induced by Aβ peptides in vitro, in HEK293 cells, and in neuronal cells. Although these results offer a possible therapeutic approach to those neurodegenerative diseases assumed to derive from Cdk5-p25 hyperactivity and/or Aβ induced pathology, CIP is too large for successful therapeutic regimens. To identify a smaller, more effective peptide, in this study we prepared a 24-residue peptide, p5, spanning CIP residues Lys(245)-Ala(277). p5 more effectively inhibited Cdk5-p25 activity than did CIP in vitro. In neuron cells, p5 inhibited deregulated Cdk5-p25 activity but had no effect on the activity of endogenous Cdk5-p35 or on any related endogenous cyclin-dependent kinases in HEK293 cells. Specificity of p5 inhibition in cortical neurons may depend on the p10 domain in p35, which is absent in p25. Furthermore, we have demonstrated that p5 reduced Aβ(1-42)-induced Tau hyperphosphorylation and apoptosis in cortical neurons. These results suggest that p5 peptide may be a unique and useful candidate for therapeutic studies of certain neurodegenerative diseases.
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Affiliation(s)
- Ya-Li Zheng
- Laboratory of Neurochemistry, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, USA
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28
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The microtubule network and neuronal morphogenesis: Dynamic and coordinated orchestration through multiple players. Mol Cell Neurosci 2009; 43:15-32. [PMID: 19660553 DOI: 10.1016/j.mcn.2009.07.012] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2009] [Accepted: 07/27/2009] [Indexed: 11/24/2022] Open
Abstract
Nervous system function and plasticity rely on the complex architecture of neuronal networks elaborated during development, when neurons acquire their specific and complex shape. During neuronal morphogenesis, the formation and outgrowth of functionally and structurally distinct axons and dendrites require a coordinated and dynamic reorganization of the microtubule cytoskeleton involving numerous regulators. While most of these factors act directly on microtubules to stabilize them or promote their assembly, depolymerization or fragmentation, others are now emerging as essential regulators of neuronal differentiation by controlling tubulin availability and modulating microtubule dynamics. In this review, we recapitulate how the microtubule network is actively regulated during the successive phases of neuronal morphogenesis, and what are the specific roles of the various microtubule-regulating proteins in that process. We then describe the specific signaling pathways and inter-regulations that coordinate the different activities of these proteins to sustain neuronal development in response to environmental cues.
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Fong KW, Hau SY, Kho YS, Jia Y, He L, Qi RZ. Interaction of CDK5RAP2 with EB1 to track growing microtubule tips and to regulate microtubule dynamics. Mol Biol Cell 2009; 20:3660-70. [PMID: 19553473 DOI: 10.1091/mbc.e09-01-0009] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Mutations in cdk5rap2 are linked to autosomal recessive primary microcephaly, and attention has been paid to its function at centrosomes. In this report, we demonstrate that CDK5RAP2 localizes to microtubules and concentrates at the distal tips in addition to centrosomal localization. CDK5RAP2 interacts directly with EB1, a prototypic member of microtubule plus-end tracking proteins, and contains the basic and Ser-rich motif responsible for EB1 binding. The EB1-binding motif is conserved in the CDK5RAP2 sequences of chimpanzee, bovine, and dog but not in those of rat and mouse, suggesting a function gained during the evolution of mammals. The mutation of the Ile/Leu-Pro dipeptide within the motif abolishes EB1 interaction and plus-end attachment. In agreement with the mutational analysis, suppression of EB1 expression inhibits microtubule tip-tracking of CDK5RAP2. We have also found that the CDK5RAP2-EB1 complex regulates microtubule dynamics and stability. CDK5RAP2 depletion by RNA interference impacts the dynamic behaviors of microtubules. The CDK5RAP2-EB1 complex induces microtubule bundling and acetylation when expressed in cell cultures and stimulates microtubule assembly and bundle formation in vitro. Collectively, these results show that CDK5RAP2 targets growing microtubule tips in association with EB1 to regulate microtubule dynamics.
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Affiliation(s)
- Ka-Wing Fong
- Department of Biochemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
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30
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Nikolic M. Unravelling the complex role of Cdk5 in the developing cerebral cortex. FUTURE NEUROLOGY 2008. [DOI: 10.2217/14796708.3.6.729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The normal development of the mammalian CNS is entirely dependent on the coordinated behavior of its cellular components. Particular importance is attributed to the correct morphology, migration and communication of neurons. Recent years have seen the identification of many extracellular, cell surface and intracellular signaling molecules that are important for normal CNS development, consequently triggering huge progress in our understanding of the complex processes involved. A key molecule to emerge is Cdk5. To date, Cdk5 has been functionally linked with controlled neuronal morphology, migration, synaptic function, cognition, drug addiction, neuronal death and neurodegeneration. The complexity of its function has been confirmed by the ever increasing number of diverse upstream regulators, protein substrates and biological consequences of altered catalytic function. The aim of this review is to consolidate recent findings concerning the role of Cdk5 in the developing nervous system, particularly the cerebral cortex, where its importance is most clearly evidenced.
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Affiliation(s)
- Margareta Nikolic
- Department of Cellular & Molecular Neuroscience, Division of Neuroscience & Mental Health, School of Medicine, Imperial College London, Burlington Danes Building, Hammersmith Campus, Du Cane Road, London, W12 0NN, UK
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31
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Kähler AK, Djurovic S, Kulle B, Jönsson EG, Agartz I, Hall H, Opjordsmoen S, Jakobsen KD, Hansen T, Melle I, Werge T, Steen VM, Andreassen OA. Association analysis of schizophrenia on 18 genes involved in neuronal migration: MDGA1 as a new susceptibility gene. Am J Med Genet B Neuropsychiatr Genet 2008; 147B:1089-100. [PMID: 18384059 DOI: 10.1002/ajmg.b.30726] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Several lines of evidence support the theory of schizophrenia (SZ) being a neurodevelopmental disorder. The structural, cytoarchitectural and functional brain abnormalities reported in patients with SZ, might be due to aberrant neuronal migration, since the final position of neurons affects neuronal function, morphology, and formation of synaptic connections. We have investigated the putative association between SZ and gene variants engaged in the neuronal migration process, by performing an association study on 839 cases and 1,473 controls of Scandinavian origin. Using a gene-wide approach, tagSNPs in 18 candidate genes have been genotyped, with gene products involved in the neuron-to-glial cell adhesion, interactions with the DISC1 protein and/or rearrangements of the cytoskeleton. Of the 289 markers tested, 19 markers located in genes MDGA1, RELN, ITGA3, DLX1, SPARCL1, and ASTN1, attained nominal significant P-values (P < 0.05) in either a genotypic or allelic association test. All of these genes, except transcription factor DLX1, are involved in the adhesion between neurons and radial glial cells. Eight markers obtained nominal significance in both tests, and were located in intronic or 3'UTR regions of adhesion molecule MDGA1 and previously reported SZ candidate RELN. The most significant result was attained for MDGA1 SNP rs9462341 (unadjusted association results: genotypic P = 0.00095; allelic P = 0.010). Several haplotypes within MDGA1, RELN, ITGA3, and ENAH were nominally significant. Further studies in independent samples are needed, including upcoming genome wide association study results, but our data suggest that MDGA1 is a new SZ susceptibility gene, and that altered neuronal migration is involved in SZ pathology.
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Affiliation(s)
- Anna K Kähler
- TOP Project, Institute of Psychiatry, University of Oslo, Oslo, Norway.
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Suppression of mutant Huntingtin aggregate formation by Cdk5/p35 through the effect on microtubule stability. J Neurosci 2008; 28:8747-55. [PMID: 18753376 DOI: 10.1523/jneurosci.0973-08.2008] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Huntington's disease (HD) is a polyglutamine [poly(Q)] disease with an expanded poly(Q) stretch in the N terminus of the huntingtin protein (htt). A major pathological feature of HD neurons is inclusion bodies, detergent-insoluble aggregates composed of poly(Q)-expanded mutant htt (mhtt). Misfolding of mhtt is thought to confer a toxic property via formation of aggregates. Although toxic molecular species are still debated, it is important to clarify the aggregation mechanism to understand the pathogenesis of mhtt. We show Cdk5/p35 suppresses the formation of mhtt inclusion bodies in cell lines and primary neurons. Although we expressed the N-terminal exon 1 fragment of htt lacking phosphorylation sites for Cdk5 in COS-7 cells, the kinase activity of Cdk5 was required for the suppression. Furthermore, Cdk5/p35 suppressed inclusion formation of atrophin-1, another poly(Q) protein, raising the possibility that Cdk5/p35 generally suppresses inclusion formation of poly(Q) proteins. Microtubules (MTs) were a downstream component of Cdk5/p35 in the suppression of inclusion formation; Cdk5/p35 disrupted MTs, which were required for the formation of inclusions. Moreover, stabilization of MTs by Taxol induced inclusions even with overexpression of Cdk5/p35. The formation of inclusions was also regulated by manipulating the Cdk5/p35 activity in primary rat or mouse cortical neuron cultures. These results indicate that Cdk5-dependent regulation of MT organization is involved in the development of aggregate formation and subsequent pathogenesis of poly(Q) diseases. This Cdk5 inhibition of htt aggregates is a novel mechanism different from htt phosphorylation and interaction with Cdk5 reported previously (Luo et al., 2005; Anne et al., 2007).
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He L, Hou Z, Qi RZ. Calmodulin Binding and Cdk5 Phosphorylation of p35 Regulate Its Effect on Microtubules. J Biol Chem 2008; 283:13252-60. [DOI: 10.1074/jbc.m706937200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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34
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Pandithage R, Lilischkis R, Harting K, Wolf A, Jedamzik B, Lüscher-Firzlaff J, Vervoorts J, Lasonder E, Kremmer E, Knöll B, Lüscher B. The regulation of SIRT2 function by cyclin-dependent kinases affects cell motility. ACTA ACUST UNITED AC 2008; 180:915-29. [PMID: 18332217 PMCID: PMC2265402 DOI: 10.1083/jcb.200707126] [Citation(s) in RCA: 163] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Cyclin-dependent kinases (Cdks) fulfill key functions in many cellular processes, including cell cycle progression and cytoskeletal dynamics. A limited number of Cdk substrates have been identified with few demonstrated to be regulated by Cdk-dependent phosphorylation. We identify on protein expression arrays novel cyclin E–Cdk2 substrates, including SIRT2, a member of the Sirtuin family of NAD+-dependent deacetylases that targets α-tubulin. We define Ser-331 as the site phosphorylated by cyclin E–Cdk2, cyclin A–Cdk2, and p35–Cdk5 both in vitro and in cells. Importantly, phosphorylation at Ser-331 inhibits the catalytic activity of SIRT2. Gain- and loss-of-function studies demonstrate that SIRT2 interfered with cell adhesion and cell migration. In postmitotic hippocampal neurons, neurite outgrowth and growth cone collapse are inhibited by SIRT2. The effects provoked by SIRT2, but not those of a nonphosphorylatable mutant, are antagonized by Cdk-dependent phosphorylation. Collectively, our findings identify a posttranslational mechanism that controls SIRT2 function, and they provide evidence for a novel regulatory circuitry involving Cdks, SIRT2, and microtubules.
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Affiliation(s)
- Ruwin Pandithage
- Abteilung Biochemie und Molekularbiologie, Institut für Biochemie, Universitätsklinikum, Rheinisch-Westfälische Technische Hochschule Aachen University, 52057 Aachen, Germany
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35
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Lukong KE, Richard S. Breast tumor kinase BRK requires kinesin-2 subunit KAP3A in modulation of cell migration. Cell Signal 2007; 20:432-42. [PMID: 18077133 DOI: 10.1016/j.cellsig.2007.11.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2007] [Revised: 11/05/2007] [Accepted: 11/06/2007] [Indexed: 10/22/2022]
Abstract
BReast tumor Kinase (BRK) also known as protein kinase 6 (PTK6) is a nonreceptor tyrosine kinase overexpressed in the majority of human breast tumors. Although some studies have implicated BRK in signalling, cell proliferation and migration, the precise intracellular role of BRK has not been fully elucidated. The RNA-binding protein Sam68, and adaptor proteins paxillin and STAT3 are the only BRK substrates that link BRK to signal transduction. To identify new BRK substrates, we screened high-density protein filter arrays by large-scale in vitro kinase assays using active recombinant BRK. We identified at least 4 BRK targets comprising the alpha-subunit of stimulatory guanine nucleotide binding protein (GNAS), FL139441, beta-tubulin and kinesin associated protein 3A (KAP3A) and validated them as BRK substrates using a secondary assay. Further characterization revealed that KAP3A is an in vivo substrate of BRK and associates with BRK in breast cancer cells. We show that BRK specifically phosphorylated tyrosine residues at the C-terminus of KAP3A and induces delocalization of KAP3A from punctate nuclear localization to a diffuse nucleo-cytoplasmic pattern. Functionally, we demonstrate that KAP3A knockdown results in suppression of BRK-induced migration of breast cancer cells and show that the C-terminal deletion mutant of KAP3A acts as a dominant negative in BRK-induced cell migration. Our findings therefore reveal new substrates of BRK and define KAP3A as a physiological substrate of BRK during cell migration.
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Affiliation(s)
- Kiven E Lukong
- Terry Fox Molecular Oncology Group and the Bloomfield Center for Research on Aging, Lady Davis Institute for Medical Research, Sir Mortimer B. Davis Jewish General Hospital, Montréal Québec, Canada
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