51
|
Webb SE, Miller AL. Calcium signaling in extraembryonic domains during early teleost development. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2014; 304:369-418. [PMID: 23809440 DOI: 10.1016/b978-0-12-407696-9.00007-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
It is becoming recognized that the extraembryonic domains of developing vertebrates, that is, those that make no cellular contribution to the embryo proper, act as important signaling centers that induce and pattern the germ layers and help establish the key embryonic axes. In the embryos of teleost fish, in particular, significant progress has been made in understanding how signaling activity in extraembryonic domains, such as the enveloping layer, the yolk syncytial layer, and the yolk cell, might help regulate development via a combination of inductive interactions, cellular dynamics, and localized gene expression. Ca(2+) signaling in a variety of forms that include propagating waves and standing gradients is a feature found in all three teleostean extraembryonic domains. This leads us to propose that in addition to their other well-characterized signaling activities, extraembryonic domains are well suited (due to their relative stability and continuity) to act as Ca(2+) signaling centers and conduits.
Collapse
Affiliation(s)
- Sarah E Webb
- Division of Life Science and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China
| | | |
Collapse
|
52
|
Abstract
Axon development and elongation require strictly controlled new membrane addition. Previously, we have shown the involvement of Rab10 in directional membrane insertion of plasmalemmal precursor vesicles (PPVs) during neuronal polarization and axonal growth. However, the mechanism responsible for PPV transportation remains unclear. Here we show that c-Jun N-terminal kinase-interacting protein 1 (JIP1) interacts with GTP-locked active form of Rab10 and directly connects Rab10 to kinesin-1 light chain (KLC). The kinesin-1/JIP1/Rab10 complex is required for anterograde transport of PPVs during axonal growth. Downregulation of JIP1 or KLC or disrupting the formation of this complex reduces anterograde transport of PPVs in developing axons and causes neuronal polarity defect. Furthermore, this complex plays an important role in neocortical neuronal polarization of rats in vivo. Thus, this study has demonstrated a mechanism underlying directional membrane trafficking involved in axon development.
Collapse
|
53
|
Mishima T, Fujiwara T, Sanada M, Kofuji T, Kanai-Azuma M, Akagawa K. Syntaxin 1B, but not syntaxin 1A, is necessary for the regulation of synaptic vesicle exocytosis and of the readily releasable pool at central synapses. PLoS One 2014; 9:e90004. [PMID: 24587181 PMCID: PMC3938564 DOI: 10.1371/journal.pone.0090004] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 01/24/2014] [Indexed: 11/24/2022] Open
Abstract
Two syntaxin 1 (STX1) isoforms, HPC-1/STX1A and STX1B, are coexpressed in neurons and function as neuronal target membrane (t)-SNAREs. However, little is known about their functional differences in synaptic transmission. STX1A null mutant mice develop normally and do not show abnormalities in fast synaptic transmission, but monoaminergic transmissions are impaired. In the present study, we found that STX1B null mutant mice died within 2 weeks of birth. To examine functional differences between STX1A and 1B, we analyzed the presynaptic properties of glutamatergic and GABAergic synapses in STX1B null mutant and STX1A/1B double null mutant mice. We found that the frequency of spontaneous quantal release was lower and the paired-pulse ratio of evoked postsynaptic currents was significantly greater in glutamatergic and GABAergic synapses of STX1B null neurons. Deletion of STX1B also accelerated synaptic vesicle turnover in glutamatergic synapses and decreased the size of the readily releasable pool in glutamatergic and GABAergic synapses. Moreover, STX1A/1B double null neurons showed reduced and asynchronous evoked synaptic vesicle release in glutamatergic and GABAergic synapses. Our results suggest that although STX1A and 1B share a basic function as neuronal t-SNAREs, STX1B but not STX1A is necessary for the regulation of spontaneous and evoked synaptic vesicle exocytosis in fast transmission.
Collapse
Affiliation(s)
- Tatsuya Mishima
- Department of Cell Physiology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
- * E-mail:
| | - Tomonori Fujiwara
- Department of Cell Physiology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Masumi Sanada
- Department of Cell Physiology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Takefumi Kofuji
- Radio Isotope Laboratory, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Masami Kanai-Azuma
- Department of Anatomy, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Kimio Akagawa
- Department of Cell Physiology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| |
Collapse
|
54
|
Chakraborty J, Rajamma U, Mohanakumar KP. A mitochondrial basis for Huntington's disease: therapeutic prospects. Mol Cell Biochem 2013; 389:277-91. [PMID: 24374792 DOI: 10.1007/s11010-013-1951-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2013] [Accepted: 12/19/2013] [Indexed: 01/12/2023]
Abstract
Huntington's disease (HD) is an autosomal dominant disease, with overt movement dysfunctions. Despite focused research on the basis of neurodegeneration in HD for last few decades, the mechanism for the site-specific lesion of neurons in the brain is not clear. All the explanations that partially clarify the phenomenon of neurodegeneration leads to one organelle, mitochondrion, which is severely affected in HD at the level of electron transport chain, Ca(2+) buffering efficiency and morphology. But, with the existing knowledge, it is not clear whether the cell death processes in HD initiate from mitochondria, though the Huntingtin (Htt) aggregates show close proximity to this organelle, or do some extracellular stimuli like TNFα or FasL trigger the process. Mainly because of the disparity in the different available experimental models, the results are quite confusing or at least inconsistent to a great extent. The fact remains that the mutant Htt protein was seen to be associated with mitochondria directly, and as the striatum is highly enriched with dopamine and glutamate, it may make the striatal mitochondria more vulnerable because of the presence of dopa-quinones, and due to an imbalance in Ca(2+). The current therapeutic strategies are based on symptomatic relief, and, therefore, mainly target neurotransmitter(s) and their receptors to modulate behavioral outputs, but none of them targets mitochondria or try to address the basic molecular events that cause neurons to die in discrete regions of the brain, which could probably be resulting from grave mitochondrial dysfunctions. Therefore, targeting mitochondria for their protection, while addressing symptomatic recovery, holds a great potential to tone down the progression of the disease, and to provide better relief to the patients and caretakers.
Collapse
Affiliation(s)
- J Chakraborty
- Laboratory of Clinical and Experimental Neuroscience, Division of Cell Biology & Physiology, CSIR-Indian Institute of Chemical Biology, Rooms 117&119, 4, Raja S. C. Mullick Road, Kolkata, 700 032, India
| | | | | |
Collapse
|
55
|
Tanifuji S, Funakoshi-Tago M, Ueda F, Kasahara T, Mochida S. Dynamin isoforms decode action potential firing for synaptic vesicle recycling. J Biol Chem 2013; 288:19050-9. [PMID: 23687302 DOI: 10.1074/jbc.m112.445874] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Presynaptic nerve terminals must maintain stable neurotransmission via synaptic vesicle membrane recycling despite encountering wide fluctuations in the number and frequency of incoming action potentials (APs). However, the molecular mechanism linking variation in neuronal activity to vesicle trafficking is unknown. Here, we combined genetic knockdown and direct physiological measurements of synaptic transmission from paired neurons to show that three isoforms of dynamin, an essential endocytic protein, work individually to match vesicle reuse pathways, having distinct rate and time constants with physiological AP frequencies. Dynamin 3 resupplied the readily releasable pool with slow kinetics independently of the AP frequency but acted quickly, within 20 ms of the incoming AP. Under high-frequency firing, dynamin 1 regulated recycling to the readily releasable pool with fast kinetics in a slower time window of greater than 50 ms. Dynamin 2 displayed a hybrid response between the other isoforms. Collectively, our findings show how dynamin isoforms select appropriate vesicle reuse pathways associated with specific neuronal firing patterns.
Collapse
Affiliation(s)
- Shota Tanifuji
- Department of Physiology, Tokyo Medical University, Tokyo 160-8402, Japan
| | | | | | | | | |
Collapse
|
56
|
Campbell PD, Marlow FL. Temporal and tissue specific gene expression patterns of the zebrafish kinesin-1 heavy chain family, kif5s, during development. Gene Expr Patterns 2013; 13:271-9. [PMID: 23684767 DOI: 10.1016/j.gep.2013.05.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 05/01/2013] [Accepted: 05/04/2013] [Indexed: 12/25/2022]
Abstract
Homo- and heterodimers of Kif5 proteins form the motor domain of Kinesin-1, a major plus-end directed microtubule motor. Kif5s have been implicated in the intracellular transport of organelles, vesicles, proteins, and RNAs in many cell types. There are three mammalian KIF5s. KIF5A and KIF5C proteins are strictly neural in mouse whereas, KIF5B is ubiquitously expressed. Mouse knockouts indicate crucial roles for KIF5 in development and human mutations in KIF5A lead to the neurodegenerative disease Hereditary Spastic Paraplegia. However, the developmental functions and the extent to which individual kif5 functions overlap have not been elucidated. Zebrafish possess five kif5 genes: kif5Aa, kif5Ab, kif5Ba, kif5Bb, and kif5C. Here we report their tissue specific expression patterns in embryonic and larval stages. Specifically, we find that kif5As are strictly zygotic and exhibit neural-specific expression. In contrast, kif5Bs exhibit strong maternal contribution and are ubiquitously expressed. Lastly, kif5C exhibits weak maternal expression followed by enrichment in neural populations. In addition, kif5s show distinct expression domains in the larval retina.
Collapse
Affiliation(s)
- Philip D Campbell
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Yeshiva University, Bronx, NY 10461, USA
| | | |
Collapse
|
57
|
DuBoff B, Feany M, Götz J. Why size matters - balancing mitochondrial dynamics in Alzheimer's disease. Trends Neurosci 2013; 36:325-35. [PMID: 23582339 DOI: 10.1016/j.tins.2013.03.002] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Revised: 03/07/2013] [Accepted: 03/11/2013] [Indexed: 12/31/2022]
Abstract
Once perceived as solitary structures, mitochondria are now recognized as highly dynamic, interconnected organelles. The tight control of their fusion and fission, a process termed 'mitochondrial dynamics', is crucial for neurons, given their unique architecture and special energy and calcium-buffering requirements at the synapse. Interestingly, in Alzheimer's disease (AD), a condition initiated at the synapse, mitochondrial dynamics are severely impaired. Of the two proteins implicated in AD pathogenesis, amyloid-β (Aβ) and TAU, only the impact of Aβ on mitochondrial dynamics has been studied in detail. We highlight recent findings that TAU exerts a determinative effect in the regulation of mitochondrial dynamics, and therefore neuronal function. In this process, the GTPase DRP1 has emerged as a key target of both Aβ and TAU.
Collapse
Affiliation(s)
- Brian DuBoff
- Brigham and Women's Hospital and Harvard Medical School, Department of Pathology, Brigham and Women's Hospital, Harvard New Research Building, Room 630, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
| | | | | |
Collapse
|
58
|
Riemer J, Kins S. Axonal Transport and Mitochondrial Dysfunction in Alzheimer's Disease. NEURODEGENER DIS 2013; 12:111-24. [DOI: 10.1159/000342020] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Accepted: 07/19/2012] [Indexed: 11/19/2022] Open
|
59
|
Regulation of cell polarity and RNA localization in vertebrate oocytes. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 306:127-85. [PMID: 24016525 DOI: 10.1016/b978-0-12-407694-5.00004-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
It has long been appreciated that the inheritance of maternal cytoplasmic determinants from different regions of the egg can lead to differential specification of blastomeres during cleavage. Localized RNAs are important determinants of cell fate in eggs and embryos but are also recognized as fundamental regulators of cell structure and function. This chapter summarizes recent molecular and genetic experiments regarding: (1) mechanisms that regulate polarity during different stages of vertebrate oogenesis, (2) pathways that localize presumptive protein and RNA determinants within the polarized oocyte and egg, and (3) how these determinants act in the embryo to determine the ultimate cell fates. Emphasis is placed on studies done in Xenopus, where extensive work has been done in these areas, and comparisons are drawn with fish and mammals. The prospects for future work using in vivo genome manipulation and other postgenomic approaches are also discussed.
Collapse
|
60
|
Ying Y, Li L, Cao W, Yan D, Zeng Q, Kong X, Lu L, Yan M, Xu X, Qu J, Su Q, Ma X. The microtubule associated protein syntabulin is required for glucose-stimulated and cAMP-potentiated insulin secretion. FEBS Lett 2012; 586:3674-80. [PMID: 22975310 DOI: 10.1016/j.febslet.2012.08.025] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Revised: 08/23/2012] [Accepted: 08/25/2012] [Indexed: 12/23/2022]
Abstract
Syntabulin is a microtubule-associated protein that mediates anterograde transport of vesicles to neuronal processes. Here, we found that syntabulin was expressed in mouse pancreas and insulin-secreting β-cells, and that it partially co-localized with microtubule and insulin-containing granules. The association of syntabulin with these organelles increased upon glucose stimulation. Knock-down of syntabulin by shRNA reduced both basal and glucose-stimulated insulin secretion, and diminished cAMP-Epac2 and cAMP-PKA potentiated insulin secretion. Additionally, syntabulin was preferentially phosphorylated by the Epac2 agonist 8-pCPT-2'-O-Me-cAMP, suggesting that syntabulin could be a novel effector of Epac2 and play a critical role in cAMP-enhanced insulin secretion.
Collapse
Affiliation(s)
- Ying Ying
- Dept. of Physiology, School of Medicine, Shenzhen University, Shenzhen 518060, PR China
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
61
|
Horii Y, Nogami S, Kawano Y, Kaneko-Kawano T, Ohtomo N, Tomiya T, Shirataki H. Interaction of α-taxilin localized on intracellular components with the microtubule cytoskeleton. Cell Struct Funct 2012; 37:111-26. [PMID: 22785156 DOI: 10.1247/csf.12002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Intracellular vesicle traffic plays an essential role in the establishment and maintenance of organelle identity and biosynthetic transport. We have identified α-taxilin as a binding partner of the syntaxin family, which is involved in intracellular vesicle traffic. Recently, we have found that α-taxilin is over-expressed in malignant tissues including hepatocellular carcinoma and renal cell carcinoma. However, a precise role of α-taxilin in intracellular vesicle traffic and carcinogenesis remains unclear. Then, we first investigated here the intracellular distribution of α-taxilin in Hela cells. Immunofluorescence studies showed that α-taxilin distributes throughout the cytoplasm and exhibits a tubulo-vesicular pattern. Biochemical studies showed that α-taxilin is abundantly localized on intracellular components as a peripheral membrane protein. Moreover, we found that α-taxilin distributes in microtubule-dependent and syntaxin-independent manners, that α-taxilin directly binds to polymerized tubulin in vitro, and that N-ethylmaleimide but not brefeldin A affects the intracellular distribution of α-taxilin. These results indicate that α-taxilin is localized on intracellular components in a syntaxin-independent manner and that the α-taxilin-containing intracellular components are associated with the microtubule cytoskeleton and suggest that α-taxilin functions as a linker protein between the α-taxilin-containing intracellular components and the microtubule cytoskeleton.
Collapse
Affiliation(s)
- Yukimi Horii
- Department of Molecular and Cell Biology, Graduate School of Medicine, Dokkyo Medical University, Tochigi, Japan
| | | | | | | | | | | | | |
Collapse
|
62
|
Abstract
SIGNIFICANCE Synaptic degeneration, an early pathological feature in Alzheimer's disease (AD), is closely correlated to impaired cognitive function and memory loss. Recent studies suggest that involvement of amyloid-beta peptide (Aβ) in synaptic mitochondrial alteration underlies these synaptic lesions. Thus, to understand the Aβ-associated synaptic mitochondrial perturbations would fortify our understanding of synaptic stress in the pathogenesis of AD. RECENT ADVANCES Increasing evidence suggests that synaptic mitochondrial dysfunction is strongly associated with synaptic failure in many neurodegenerative diseases including AD. Based on recent findings in human AD subjects, AD animal models, and AD cellular models, synaptic mitochondria undergo multiple malfunctions including Aβ accumulation, increased oxidative stress, decreased respiration, and compromised calcium handling capacity, all of which occur earlier than changes seen in nonsynaptic mitochondria before predominant AD pathology. Of note, the impact of Aβ on mitochondrial motility and dynamics exacerbates synaptic mitochondrial alterations. CRITICAL ISSUES Synaptic mitochondria demonstrate early deficits in AD; in combination with the role that synaptic mitochondria play in sustaining synaptic functions, deficits in synaptic mitochondria may be a key factor involved in an early synaptic pathology in AD. FUTURE DIRECTIONS The importance of synaptic mitochondria in supporting synapses and the high vulnerability of synaptic mitochondria to Aβ make them a promising target of new therapeutic strategy for AD.
Collapse
Affiliation(s)
- Heng Du
- Higuchi Bioscience Center, University of Kansas, Lawrence, Kansas, USA
| | | | | |
Collapse
|
63
|
Abstract
Vigorous transport of cytoplasmic components along axons over substantial distances is crucial for the maintenance of neuron structure and function. The transport of mitochondria, which serves to distribute mitochondrial functions in a dynamic and non-uniform fashion, has attracted special interest in recent years following the discovery of functional connections among microtubules, motor proteins and mitochondria, and their influences on neurodegenerative diseases. Although the motor proteins that drive mitochondrial movement are now well characterized, the mechanisms by which anterograde and retrograde movement are coordinated with one another and with stationary axonal mitochondria are not yet understood. In this Commentary, we review why mitochondria move and how they move, focusing particularly on recent studies of transport regulation, which implicate control of motor activity by specific cell-signaling pathways, regulation of motor access to transport tracks and static microtubule-mitochondrion linkers. A detailed mechanism for modulating anterograde mitochondrial transport has been identified that involves Miro, a mitochondrial Ca(2+)-binding GTPase, which with associated proteins, can bind and control kinesin-1. Elements of the Miro complex also have important roles in mitochondrial fission-fusion dynamics, highlighting questions about the interdependence of biogenesis, transport, dynamics, maintenance and degradation.
Collapse
Affiliation(s)
- William M Saxton
- Department of Molecular Cell and Developmental Biology, University of California, Cruz, CA 95060, USA.
| | | |
Collapse
|
64
|
Wang W, Lundin VF, Millan I, Zeng A, Chen X, Yang J, Allen E, Chen N, Bach G, Hsu A, Maloney MT, Kapur M, Yang Y. Nemitin, a novel Map8/Map1s interacting protein with Wd40 repeats. PLoS One 2012; 7:e33094. [PMID: 22523538 PMCID: PMC3327699 DOI: 10.1371/journal.pone.0033094] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Accepted: 02/03/2012] [Indexed: 11/18/2022] Open
Abstract
In neurons, a highly regulated microtubule cytoskeleton is essential for many cellular functions. These include axonal transport, regional specialization and synaptic function. Given the critical roles of microtubule-associated proteins (MAPs) in maintaining and regulating microtubule stability and dynamics, we sought to understand how this regulation is achieved. Here, we identify a novel LisH/WD40 repeat protein, tentatively named nemitin (neuronal enriched MAP interacting protein), as a potential regulator of MAP8-associated microtubule function. Based on expression at both the mRNA and protein levels, nemitin is enriched in the nervous system. Its protein expression is detected as early as embryonic day 11 and continues through adulthood. Interestingly, when expressed in non-neuronal cells, nemitin displays a diffuse pattern with puncta, although at the ultrastructural level it localizes along the microtubule network in vivo in sciatic nerves. These results suggest that the association of nemitin to microtubules may require an intermediary protein. Indeed, co-expression of nemitin with microtubule-associated protein 8 (MAP8) results in nemitin losing its diffuse pattern, instead decorating microtubules uniformly along with MAP8. Together, these results imply that nemitin may play an important role in regulating the neuronal cytoskeleton through an interaction with MAP8.
Collapse
Affiliation(s)
- Wei Wang
- Department of Neurology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Victor F. Lundin
- Department of Neurology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Ivan Millan
- Department of Neurology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Anne Zeng
- Department of Neurology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Xinyu Chen
- Department of Biochemistry and Cell Biology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jie Yang
- Department of Biochemistry and Cell Biology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Elizabeth Allen
- Department of Neurology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Ningna Chen
- Department of Neurology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Gillian Bach
- Department of Neurology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Andrew Hsu
- Department of Neurology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Michael T. Maloney
- Department of Neurology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Mridu Kapur
- Department of Neurology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Yanmin Yang
- Department of Neurology, Stanford University School of Medicine, Stanford, California, United States of America
- * E-mail:
| |
Collapse
|
65
|
MacDonald JIS, Dietrich A, Gamble S, Hryciw T, Grant RI, Meakin SO. Nesca, a novel neuronal adapter protein, links the molecular motor kinesin with the pre-synaptic membrane protein, syntaxin-1, in hippocampal neurons. J Neurochem 2012; 121:861-80. [PMID: 22404429 DOI: 10.1111/j.1471-4159.2012.07729.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Vesicular transport in neurons plays a vital role in neuronal function and survival. Nesca is a novel protein that we previously identified and herein describe its pattern of expression, subcellular localization and protein-protein interactions both in vitro and in vivo. Specifically, a large proportion of Nesca is in tight association with both actin and microtubule cytoskeletal proteins. Nesca binds to F-actin, microtubules, βIII and acetylated α-tubulin, but not neurofilaments or the actin-binding protein drebrin, in in vitro-binding assays. Nesca co-immunoprecipitates with kinesin heavy chain (KIF5B) and kinesin light-chain motors as well as with the synaptic membrane precursor protein, syntaxin-1, and is a constituent of the post-synaptic density. Moreover, in vitro-binding assays indicate that Nesca directly binds KIF5B, kinesin light-chain and syntaxin-1. In contrast, Nesca does not co-immunoprecipitate with the kinesin motors KIF1B, KIF3A nor does it bind syntaxin-4 or the synaptosome-associated protein 25 kDa (SNAP-25) in vitro. Nesca expression in neurons is highly punctuate, co-stains with syntaxin-1, and is found in fractions containing markers of early endosomes and Golgi suggesting that it is involved in vesicular transport. Collectively, these data suggest that Nesca functions as an adapter involved in neuronal vesicular transport including vesicles containing soluble N-ethylmaleimide sensitive factor attachment protein receptors that are essential to exocytosis.
Collapse
Affiliation(s)
- James I S MacDonald
- Laboratory of Neural Signaling, Molecular Brain Research Group, Robarts Research Institute, Schulich School of Medicine, University of Western Ontario, London, ON, Canada
| | | | | | | | | | | |
Collapse
|
66
|
Abstract
Hereditary spastic paraplegia (HSP) is a neurodegenerative disorder preferentially affecting the longest corticospinal axons. More than 40 HSP genetic loci have been identified, among them SPG10, an autosomal dominant HSP caused by point mutations in the neuronal kinesin heavy chain protein KIF5A. Constitutive KIF5A knockout (KIF5A–/–) mice die early after birth. In these mice, lungs were unexpanded, and cell bodies of lower motor neurons in the spinal cord swollen, but the pathomechanism remained unclear. To gain insights into the pathophysiology, we characterized survival, outgrowth, and function in primary motor and sensory neuron cultures from KIF5A–/– mice. Absence of KIF5A reduced survival in motor neurons, but not in sensory neurons. Outgrowth of axons and dendrites was remarkably diminished in KIF5A–/– motor neurons. The number of axonal branches was reduced, whereas the number of dendrites was not altered. In KIF5A–/– sensory neurons, neurite outgrowth was decreased but the number of neurites remained unchanged. In motor neurons maximum and average velocity of mitochondrial transport was reduced both in anterograde and retrograde direction. Our results point out a role of KIF5A in process outgrowth and axonal transport of mitochondria, affecting motor neurons more severely than sensory neurons. This gives pathophysiological insights into KIF5A associated HSP, and matches the clinical findings of predominant degeneration of the longest axons of the corticospinal tract.
Collapse
|
67
|
Phosphorylation-regulated axonal dependent transport of syntaxin 1 is mediated by a Kinesin-1 adapter. Proc Natl Acad Sci U S A 2012; 109:5862-7. [PMID: 22451907 DOI: 10.1073/pnas.1113819109] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Presynaptic nerve terminals are formed from preassembled vesicles that are delivered to the prospective synapse by kinesin-mediated axonal transport. However, precisely how the various cargoes are linked to the motor proteins remains unclear. Here, we report a transport complex linking syntaxin 1a (Stx) and Munc18, two proteins functioning in synaptic vesicle exocytosis at the presynaptic plasma membrane, to the motor protein Kinesin-1 via the kinesin adaptor FEZ1. Mutation of the FEZ1 ortholog UNC-76 in Caenorhabditis elegans causes defects in the axonal transport of Stx. We also show that binding of FEZ1 to Kinesin-1 and Munc18 is regulated by phosphorylation, with a conserved site (serine 58) being essential for binding. When expressed in C. elegans, wild-type but not phosphorylation-deficient FEZ1 (S58A) restored axonal transport of Stx. We conclude that FEZ1 operates as a kinesin adaptor for the transport of Stx, with cargo loading and unloading being regulated by protein kinases.
Collapse
|
68
|
Nakayama T, Kamiguchi H, Akagawa K. Syntaxin 1C, a soluble form of syntaxin, attenuates membrane recycling by destabilizing microtubules. J Cell Sci 2012; 125:817-30. [PMID: 22421360 DOI: 10.1242/jcs.081943] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Syntaxin 1C (STX1C), produced by alternative splicing of the stx1A gene, is a soluble syntaxin lacking a SNARE domain and a transmembrane domain. It is unclear how soluble syntaxin can control intracellular membrane trafficking. We found that STX1C affected microtubule (MT) dynamics through its tubulin-binding domain (TBD) and regulated recycling of intracellular vesicles carrying glucose transporter-1 (GLUT1). We demonstrated that the amino acid sequence VRSK of the TBD was important for the interaction between STX1C and tubulin and that wild-type STX1C (STX1C-WT), but not the TBD mutant, reduced the V(max) of glucose transport and GLUT1 translocation to the plasma membrane in FRSK cells. Moreover, by time-lapse analysis, we revealed that STX1C-WT suppressed MT stability and vesicle-transport motility in cells expressing GFP-α-tubulin, whereas TBD mutants had no effect. We also identified that GLUT1 was recycled in the 45 minutes after endocytosis and that GLUT1 vesicles moved along with MTs. Finally, we showed, by a recycling assay and FCM analysis, that STX1C-WT delayed the recycling phase of GLUT1 to PM, without affecting the endocytotic process of GLUT1. These data indicate that STX1C delays the GLUT1 recycling phase by suppressing MT stability and vesicle-transport motility through its TBD, providing the first insight into how soluble syntaxin controls membrane trafficking.
Collapse
Affiliation(s)
- Takahiro Nakayama
- Department of Cell Physiology, Kyorin University School of Medicine, Tokyo, 181-8611, Japan.
| | | | | |
Collapse
|
69
|
Terminal transport of lytic granules to the immune synapse is mediated by the kinesin-1/Slp3/Rab27a complex. Blood 2012; 119:3879-89. [PMID: 22308290 DOI: 10.1182/blood-2011-09-382556] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Cytotoxic T lymphocytes kill target cells via the polarized secretion of cytotoxic granules at the immune synapse. The lytic granules are initially recruited around the polarized microtubule-organizing center. In a dynein-dependent transport process, the granules move along microtubules toward the microtubule-organizing center in the minus-end direction. Here, we found that a kinesin-1-dependent process is required for terminal transport and secretion of polarized lytic granule to the immune synapse. We show that synaptotagmin-like protein 3 (Slp3) is an effector of Rab27a in cytotoxic T lymphocytes and interacts with kinesin-1 through the tetratricopeptide repeat of the kinesin-1 light chain. Inhibition of the Rab27a/Slp3/kinesin-1 transport complex impairs lytic granule secretion. Our data provide further molecular insights into the key functional and regulatory mechanisms underlying the terminal transport of cytotoxic granules and the latter's secretion at the immune synapse.
Collapse
|
70
|
Houston DW. Cortical rotation and messenger RNA localization in Xenopus axis formation. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2012; 1:371-88. [PMID: 23801488 DOI: 10.1002/wdev.29] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In Xenopus eggs, fertilization initiates a rotational movement of the cortex relative to the cytoplasm, resulting in the transport of critical determinants to the future dorsal side of the embryo. Cortical rotation is mediated by microtubules, resulting in activation of the Wnt/β-catenin signaling pathway and expression of organizer genes on the dorsal side of the blastula. Similar cytoplasmic localizations resulting in β-catenin activation occur in many chordate embryos, suggesting a deeply conserved mechanism for patterning early embryos. This review summarizes the experimental evidence for the molecular basis of this model, focusing on recent maternal loss-of-function studies that shed light on two main unanswered questions: (1) what regulates microtubule assembly during cortical rotation and (2) how is Wnt/β-catenin signaling activated dorsally? In addition, as these processes depend on vegetally localized molecules in the oocyte, the mechanisms of RNA localization and novel roles for localized RNAs in axis formation are discussed. The work reviewed here provides a beginning framework for understanding the coupling of asymmetry in oogenesis with the establishment of asymmetry in the embryo.
Collapse
|
71
|
Matsuzaki F, Shirane M, Matsumoto M, Nakayama KI. Protrudin serves as an adaptor molecule that connects KIF5 and its cargoes in vesicular transport during process formation. Mol Biol Cell 2011; 22:4602-20. [PMID: 21976701 PMCID: PMC3226478 DOI: 10.1091/mbc.e11-01-0068] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Revised: 09/26/2011] [Accepted: 09/28/2011] [Indexed: 01/22/2023] Open
Abstract
Neurons are highly polarized cells with long neurites. Vesicular transport is required for neurite extension. We recently identified protrudin as a key regulator of vesicular transport during neurite extension. Expression of protrudin in nonneuronal cells thus induces formation of neurite-like membrane protrusions. We adopted a proteomics approach to identify proteins that associate with protrudin. Among the protrudin-associated proteins, including many with a function related to intracellular trafficking, we focused on KIF5, a motor protein that mediates anterograde vesicular transport in neurons. A coimmunoprecipitation assay confirmed that endogenous protrudin and KIF5 interact in mouse brain. Overexpression of KIF5 induced the formation of membrane protrusions in HeLa cells, reminiscent of the effect of protrudin overexpression. Forced expression of both protrudin and KIF5 promoted protrusion extension in a synergistic manner, whereas depletion of either protein attenuated protrusion formation. Protrudin facilitated the interaction of KIF5 with Rab11, VAP-A and -B, Surf4, and RTN3, suggesting that protrudin serves as an adaptor protein and that the protrudin-KIF5 complex contributes to the transport of these proteins in neurons. Given that mutation of protrudin or KIF5 is a cause of human hereditary spastic paraplegia, the protrudin-KIF5 axis appears to be integral to neuronal function.
Collapse
Affiliation(s)
- Fumiko Matsuzaki
- Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582, Japan; CREST, Japan Science and Technology Corporation (JST), Kawaguchi, Saitama 332-0012, Japan
| | - Michiko Shirane
- Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582, Japan; CREST, Japan Science and Technology Corporation (JST), Kawaguchi, Saitama 332-0012, Japan
| | - Masaki Matsumoto
- Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582, Japan; CREST, Japan Science and Technology Corporation (JST), Kawaguchi, Saitama 332-0012, Japan
| | - Keiichi I. Nakayama
- Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582, Japan; CREST, Japan Science and Technology Corporation (JST), Kawaguchi, Saitama 332-0012, Japan
| |
Collapse
|
72
|
Zhou RM, Jing YY, Guo Y, Gao C, Zhang BY, Chen C, Shi Q, Tian C, Wang ZY, Gong HS, Han J, Xu BL, Dong XP. Molecular interaction of TPPP with PrP antagonized the CytoPrP-induced disruption of microtubule structures and cytotoxicity. PLoS One 2011; 6:e23079. [PMID: 21857997 PMCID: PMC3155546 DOI: 10.1371/journal.pone.0023079] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Accepted: 07/05/2011] [Indexed: 11/30/2022] Open
Abstract
Background Tubulin polymerization promoting protein/p25 (TPPP/p25), known as a microtubule-associated protein (MAP), is a brain-specific unstructured protein with a physiological function of stabilizing cellular microtubular ultrastructures. Whether TPPP involves in the normal functions of PrP or the pathogenesis of prion disease remains unknown. Here, we proposed the data that TPPP formed molecular complex with PrP. We also investigated its influence on the aggregation of PrP and fibrillization of PrP106–126 in vitro, its antagonization against the disruption of microtubule structures and cytotoxicity of cytosolic PrP in cells, and its alternation in the brains of scrapie-infected experimental hamsters. Methodology/Principal Findings Using pull-down and immunoprecipitation assays, distinct molecular interaction between TPPP and PrP were identified and the segment of TPPP spanning residues 100–219 and the segment of PrP spanning residues 106–126 were mapped as the regions responsible for protein interaction. Sedimentation experiments found that TPPP increased the aggregation of full-length recombinant PrP (PrP23–231) in vitro. Transmission electron microscopy and Thioflavin T (ThT) assays showed that TPPP enhanced fibril formation of synthetic peptide PrP106–126 in vitro. Expression of TPPP in the cultured cells did not obviously change the microtubule networks observed by a tubulin-specific immunofluorescent assay and cell growth features measured by CCK8 tests, but significantly antagonized the disruption of microtubule structures and rescued the cytotoxicity caused by the accumulation of cytosolic PrP (CytoPrP). Furthermore, Western blots identified that the levels of the endogenous TPPP in the brains of scrapie-infected experimental hamsters were significantly reduced. Conclusion/Significance Those data highlight TPPP may work as a protective factor for cells against the damage effects of the accumulation of abnormal forms of PrPs, besides its function as an agent for dynamic stabilization of microtubular ultrastructures.
Collapse
Affiliation(s)
- Rui-Min Zhou
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
- Henan Provincial Center for Disease Control and Prevention, Zhengzhou, Henan Province, People's Republic of China
| | - Yuan-Yuan Jing
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Yan Guo
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Chen Gao
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Bao-Yun Zhang
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Cao Chen
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Qi Shi
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Chan Tian
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Zhao-Yun Wang
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Han-Shi Gong
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Jun Han
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Bian-Li Xu
- Henan Provincial Center for Disease Control and Prevention, Zhengzhou, Henan Province, People's Republic of China
| | - Xiao-Ping Dong
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
- * E-mail:
| |
Collapse
|
73
|
Sunday Driver/JIP3 binds kinesin heavy chain directly and enhances its motility. EMBO J 2011; 30:3416-29. [PMID: 21750526 DOI: 10.1038/emboj.2011.229] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2011] [Accepted: 06/21/2011] [Indexed: 01/03/2023] Open
Abstract
Neuronal development, function and repair critically depend on axonal transport of vesicles and protein complexes, which is mediated in part by the molecular motor kinesin-1. Adaptor proteins recruit kinesin-1 to vesicles via direct association with kinesin heavy chain (KHC), the force-generating component, or via the accessory light chain (KLC). Binding of adaptors to the motor is believed to engage the motor for microtubule-based transport. We report that the adaptor protein Sunday Driver (syd, also known as JIP3 or JSAP1) interacts directly with KHC, in addition to and independently of its known interaction with KLC. Using an in vitro motility assay, we show that syd activates KHC for transport and enhances its motility, increasing both KHC velocity and run length. syd binding to KHC is functional in neurons, as syd mutants that bind KHC but not KLC are transported to axons and dendrites similarly to wild-type syd. This transport does not rely on syd oligomerization with itself or other JIP family members. These results establish syd as a positive regulator of kinesin activity and motility.
Collapse
|
74
|
Bury LAD, Sabo SL. Coordinated trafficking of synaptic vesicle and active zone proteins prior to synapse formation. Neural Dev 2011; 6:24. [PMID: 21569270 PMCID: PMC3103415 DOI: 10.1186/1749-8104-6-24] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Accepted: 05/10/2011] [Indexed: 11/10/2022] Open
Abstract
Background The proteins required for synaptic transmission are rapidly assembled at nascent synapses, but the mechanisms through which these proteins are delivered to developing presynaptic terminals are not understood. Prior to synapse formation, active zone proteins and synaptic vesicle proteins are transported along axons in distinct organelles referred to as piccolo-bassoon transport vesicles (PTVs) and synaptic vesicle protein transport vesicles (STVs), respectively. Although both PTVs and STVs are recruited to the same site in the axon, often within minutes of axo-dendritic contact, it is not known whether or how PTV and STV trafficking is coordinated before synapse formation. Results Here, using time-lapse confocal imaging of the dynamics of PTVs and STVs in the same axon, we show that vesicle trafficking is coordinated through at least two mechanisms. First, a significant proportion of STVs and PTVs are transported together before forming a stable terminal. Second, individual PTVs and STVs share pause sites within the axon. Importantly, for both STVs and PTVs, encountering the other type of vesicle increases their propensity to pause. To determine if PTV-STV interactions are important for pausing, PTV density was reduced in axons by expression of a dominant negative construct corresponding to the syntaxin binding domain of syntabulin, which links PTVs with their KIF5B motor. This reduction in PTVs had a minimal effect on STV pausing and movement, suggesting that an interaction between STVs and PTVs is not responsible for enhancing STV pausing. Conclusions Our results indicate that trafficking of STVs and PTVs is coordinated even prior to synapse development. This novel coordination of transport and pausing might provide mechanisms through which all of the components of a presynaptic terminal can be rapidly accumulated at sites of synapse formation.
Collapse
Affiliation(s)
- Luke A D Bury
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA
| | | |
Collapse
|
75
|
Cai Q, Davis ML, Sheng ZH. Regulation of axonal mitochondrial transport and its impact on synaptic transmission. Neurosci Res 2011; 70:9-15. [PMID: 21352858 PMCID: PMC3086944 DOI: 10.1016/j.neures.2011.02.005] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2010] [Revised: 02/07/2011] [Accepted: 02/07/2011] [Indexed: 12/11/2022]
Abstract
Mitochondria are essential organelles for neuronal survival and play important roles in ATP generation, calcium buffering, and apoptotic signaling. Due to their extreme polarity, neurons utilize specialized mechanisms to regulate mitochondrial transport and retention along axons and near synaptic terminals where energy supply and calcium homeostasis are in high demand. Axonal mitochondria undergo saltatory and bidirectional movement and display complex mobility patterns. In cultured neurons, approximately one-third of axonal mitochondria are mobile, while the rest remain stationary. Stationary mitochondria at synapses serve as local energy stations that produce ATP to support synaptic function. In addition, axonal mitochondria maintain local Ca²+ homeostasis at presynaptic boutons. The balance between mobile and stationary mitochondria is dynamic and responds quickly to changes in axonal and synaptic physiology. The coordination of mitochondrial mobility and synaptic activity is crucial for neuronal function synaptic plasticity. In this update article, we introduce recent advances in our understanding of the motor-adaptor complexes and docking machinery that mediate mitochondrial transport and axonal distribution. We will also discuss the molecular mechanisms underlying the complex mobility patterns of axonal mitochondria and how mitochondrial mobility impacts the physiology and function of synapses.
Collapse
Affiliation(s)
- Qian Cai
- Synaptic Function Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Building 35, Room 2B-215, 35 Convent Drive, Bethesda, Maryland 20892-3706, USA
| | - Matthew L. Davis
- Synaptic Function Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Building 35, Room 2B-215, 35 Convent Drive, Bethesda, Maryland 20892-3706, USA
| | - Zu-Hang Sheng
- Synaptic Function Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Building 35, Room 2B-215, 35 Convent Drive, Bethesda, Maryland 20892-3706, USA
| |
Collapse
|
76
|
Cui J, Wang Z, Cheng Q, Lin R, Zhang XM, Leung PS, Copeland NG, Jenkins NA, Yao KM, Huang JD. Targeted inactivation of kinesin-1 in pancreatic β-cells in vivo leads to insulin secretory deficiency. Diabetes 2011; 60:320-30. [PMID: 20870970 PMCID: PMC3012189 DOI: 10.2337/db09-1078] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE Suppression of Kinesin-1 by antisense oligonucleotides, or overexpression of dominant-negative acting kinesin heavy chain, has been reported to affect the sustained phase of glucose-stimulated insulin secretion in β-cells in vitro. In this study, we examined the in vivo physiological role of Kinesin-1 in β-cell development and function. RESEARCH DESIGN AND METHODS A Cre-LoxP strategy was used to generate conditional knockout mice in which the Kif5b gene is specifically inactivated in pancreatic β-cells. Physiological and histological analyses were carried out in Kif5b knockout mice as well as littermate controls. RESULTS Mice with β-cell specific deletion of Kif5b (Kif5b(fl/)⁻:RIP2-Cre) displayed significantly retarded growth as well as slight hyperglycemia in both nonfasting and 16-h fasting conditions compared with control littermates. In addition, Kif5b(fl/)⁻:RIP2-Cre mice displayed significant glucose intolerance, which was not due to insulin resistance but was related to an insulin secretory defect in response to glucose challenge. These defects of β-cell function in mutant mice were not coupled with observable changes in islet morphology, islet cell composition, or β-cell size. However, compared with controls, pancreas of Kif5b(fl/)⁻:RIP2-Cre mice exhibited both reduced islet size and increased islet number, concomitant with an increased insulin vesicle density in β-cells. CONCLUSIONS In addition to being essential for maintaining glucose homeostasis and regulating β-cell function, Kif5b may be involved in β-cell development by regulating β-cell proliferation and insulin vesicle synthesis.
Collapse
Affiliation(s)
- Ju Cui
- Department of Biochemistry, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Zai Wang
- Department of Biochemistry, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Qianni Cheng
- Department of Physiology, The Chinese University of Hong Kong, Hong Kong
| | - Raozhou Lin
- Department of Biochemistry, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Xin-Mei Zhang
- Department of Biochemistry, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Po Sing Leung
- Department of Physiology, The Chinese University of Hong Kong, Hong Kong
| | - Neal G. Copeland
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore
| | - Nancy A. Jenkins
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore
| | - Kwok-Ming Yao
- Department of Biochemistry, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
- Corresponding author: Jian-Dong Huang, , or Kwok-Ming Yao,
| | - Jian-Dong Huang
- Department of Biochemistry, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
- Corresponding author: Jian-Dong Huang, , or Kwok-Ming Yao,
| |
Collapse
|
77
|
Hirokawa N, Niwa S, Tanaka Y. Molecular Motors in Neurons: Transport Mechanisms and Roles in Brain Function, Development, and Disease. Neuron 2010; 68:610-38. [DOI: 10.1016/j.neuron.2010.09.039] [Citation(s) in RCA: 668] [Impact Index Per Article: 47.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/22/2010] [Indexed: 12/11/2022]
|
78
|
Cytosolic PrP Induces Apoptosis of Cell by Disrupting Microtubule Assembly. J Mol Neurosci 2010; 43:316-25. [DOI: 10.1007/s12031-010-9443-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2010] [Accepted: 08/23/2010] [Indexed: 10/19/2022]
|
79
|
Proteome analysis of microtubule-associated proteins and their interacting partners from mammalian brain. Amino Acids 2010; 41:363-85. [PMID: 20567863 DOI: 10.1007/s00726-010-0649-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2010] [Accepted: 06/01/2010] [Indexed: 10/19/2022]
Abstract
The microtubule (MT) cytoskeleton is essential for a variety of cellular processes. MTs are finely regulated by distinct classes of MT-associated proteins (MAPs), which themselves bind to and are regulated by a large number of additional proteins. We have carried out proteome analyses of tubulin-rich and tubulin-depleted MAPs and their interacting partners isolated from bovine brain. In total, 573 proteins were identified giving us unprecedented access to brain-specific MT-associated proteins from mammalian brain. Most of the standard MAPs were identified and at least 500 proteins have been reported as being associated with MTs. We identified protein complexes with a large number of subunits such as brain-specific motor/adaptor/cargo complexes for kinesins, dynein, and dynactin, and proteins of an RNA-transporting granule. About 25% of the identified proteins were also found in the synaptic vesicle proteome. Analysis of the MS/MS data revealed many posttranslational modifications, amino acid changes, and alternative splice variants, particularly in tau, a key protein implicated in Alzheimer's disease. Bioinformatic analysis of known protein-protein interactions of the identified proteins indicated that the number of MAPs and their associated proteins is larger than previously anticipated and that our database will be a useful resource to identify novel binding partners.
Collapse
|
80
|
Nojima H, Rothhämel S, Shimizu T, Kim CH, Yonemura S, Marlow FL, Hibi M. Syntabulin, a motor protein linker, controls dorsal determination. Development 2010; 137:923-33. [PMID: 20150281 DOI: 10.1242/dev.046425] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
In amphibian and teleost embryos, the dorsal determinants (DDs) are believed to be initially localized to the vegetal pole and then transported to the prospective dorsal side of the embryo along a microtubule array. The DDs are known to activate the canonical Wnt pathway and thereby promote the expression of genes that induce the dorsal organizer. Here, by identifying the locus of the maternal-effect ventralized mutant tokkaebi, we show that Syntabulin, a linker of the kinesin I motor protein, is essential for dorsal determination in zebrafish. We found that syntabulin mRNA is transported to the vegetal pole during oogenesis through the Bucky ball (Buc)-mediated Balbiani body-dependent pathway, which is necessary for establishment of animal-vegetal (AV) oocyte polarity. We demonstrate that Syntabulin is translocated from the vegetal pole in a microtubule-dependent manner. Our findings suggest that Syntabulin regulates the microtubule-dependent transport of the DDs, and provide evidence for the link between AV and dorsoventral axis formation.
Collapse
Affiliation(s)
- Hideaki Nojima
- Laboratory for Vertebrate Axis Formation, RIKEN Center for Developmental Biology, Hyogo 650-0047, Japan
| | | | | | | | | | | | | |
Collapse
|
81
|
Control of mitochondrial transport and localization in neurons. Trends Cell Biol 2009; 20:102-12. [PMID: 20006503 DOI: 10.1016/j.tcb.2009.11.002] [Citation(s) in RCA: 268] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2009] [Revised: 11/17/2009] [Accepted: 11/17/2009] [Indexed: 12/18/2022]
Abstract
Mitochondria play an essential role in ATP generation, calcium buffering and apoptotic signalling. In neurons, the transport of mitochondria to specific locations where they are needed has emerged as an important process for correct nerve cell function. Recent studies have shed light on the mechanisms that control mitochondrial transport and localization in neurons. We describe the machinery that is important for constitutive transport of mitochondria throughout the cell, and highlight recent advances in our understanding of how signalling pathways can converge on this machinery and allow for rapid activity-dependent control of mitochondrial trafficking and localization. Regulation of mitochondrial trafficking might work in concert with mitochondrial tethering systems to give precise control of mitochondrial delivery and localization to regions of high energy and calcium buffering requirements within neurons.
Collapse
|
82
|
Morton AM, Cunningham AL, Diefenbach RJ. Kinesin-1 plays a role in transport of SNAP-25 to the plasma membrane. Biochem Biophys Res Commun 2009; 391:388-93. [PMID: 19913510 DOI: 10.1016/j.bbrc.2009.11.068] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Accepted: 11/09/2009] [Indexed: 01/12/2023]
Abstract
The cellular molecular motor kinesin-1 mediates the microtubule-dependent transport of a range of cargo. We have previously identified an interaction between the cargo-binding domain of kinesin-1 heavy chain KIF5B and the membrane-associated SNARE proteins SNAP-25 and SNAP-23. In this study we further defined the minimal SNAP-25 binding domain in KIF5B to residues 874-894. Overexpression of a fragment of KIF5B (residues 594-910) resulted in significant colocalization with SNAP-25 with resulting blockage of the trafficking of SNAP-25 to the periphery of cells. This indicates that kinesin-1 facilitates the transport of SNAP-25 containing vesicles as a prerequisite to SNAP-25 driven membrane fusion events.
Collapse
Affiliation(s)
- April M Morton
- Centre for Virus Research, Westmead Millennium Institute, The University of Sydney and Westmead Hospital, Westmead, NSW 2145, Australia
| | | | | |
Collapse
|
83
|
Abstract
Newly synthesized synaptic proteins and mitochondria are transported along lengthy neuronal processes to assist in the proper assembly of developing synapses and activity-dependent remodeling of mature synapses. Neuronal transport is mediated by motor proteins that associate with their cargoes via adaptors and travel along the cytoskeleton within neuronal processes. Our previous studies in developing hippocampal neurons revealed that syntabulin acts as a KIF5B motor adaptor and mediates anterograde transport of presynaptic cargoes and mitochondria, presynaptic assembly, and activity-induced plasticity. Here, using cultured superior cervical ganglion neurons combined with manipulation of syntabulin expression or interference with its interaction with KIF5B, we uncover a crucial role for syntabulin in the maintenance of presynaptic function. Syntabulin loss-of-function delayed the appearance of synaptic activity in developing neurons and impaired synaptic transmission in mature neurons, including reduced basal activity, accelerated synaptic depression under high-frequency firing, slowed recovery rates after synaptic vesicle depletion, and impaired presynaptic short-term plasticity. These defects correlated with reduced mitochondrial distribution along neuronal processes and were rescued by the application of ATP within presynaptic neurons. These results suggest that syntabulin supports the axonal transport of mitochondria and concomitant ATP production at presynaptic terminals. ATP supply from locally stationed mitochondria is in turn necessary for the efficient mobilization of synaptic vesicles into the readily releasable pool. These findings emphasize the critical role of KIF5B-syntabulin-mediated axonal transport in the maintenance of presynaptic function and regulation of synaptic plasticity.
Collapse
|
84
|
Molecular interaction of α-synuclein with tubulin influences on the polymerization of microtubule in vitro and structure of microtubule in cells. Mol Biol Rep 2009; 37:3183-92. [PMID: 19826908 DOI: 10.1007/s11033-009-9899-2] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2009] [Accepted: 10/02/2009] [Indexed: 12/23/2022]
Abstract
Microtubule dynamics is essential for many vital cellular processes such as in intracellular transport, metabolism, and cell division. Evidences demonstrate that α-synuclein may associate with microtubular cytoskeleton and its major component, tubulin. In the present study, the molecular interaction between α-synuclein and tubulin was confirmed by GST pull-down assay and co-immunoprecipitation. The interacting regions within α-synuclein with tubulin were mapped at the residues 60-100 of α-synuclein that is critical for the binding activity with tubulin. Microtubule assembly assays and sedimentation tests demonstrated that α-synuclein influenced the polymerization of tubulin in vitro, revealing an interacting region-dependent feature. Confocal microscopy detected that exposures of α-synuclein proteins inhibited microtubule formation in the cultured cells, with a length-dependent phenomenon. Our data highlight a potential role of α-synuclein in regulating the microtubule dynamics in neurons. The association of α-synuclein with tubulin may further provide insight into the biological and pathophysiological function of synuclein.
Collapse
|
85
|
Abstract
Intracellular transport is fundamental for cellular function, survival and morphogenesis. Kinesin superfamily proteins (also known as KIFs) are important molecular motors that directionally transport various cargos, including membranous organelles, protein complexes and mRNAs. The mechanisms by which different kinesins recognize and bind to specific cargos, as well as how kinesins unload cargo and determine the direction of transport, have now been identified. Furthermore, recent molecular genetic experiments have uncovered important and unexpected roles for kinesins in the regulation of such physiological processes as higher brain function, tumour suppression and developmental patterning. These findings open exciting new areas of kinesin research.
Collapse
|
86
|
Abstract
The paradigm for soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNARE) function in mammalian cells has been built on advancements in our understanding of structural and biochemical aspects of synaptic vesicle exocytosis, involving specifically synaptobrevin, syntaxin 1 and SNAP25. Interestingly, a good number of SNAREs which are not directly involved in neurotransmitter exocytosis, are either brain-enriched or have distinct neuron-specific functions. Syntaxins 12/13 regulates glutamate receptor recycling via its interaction with neuron-enriched endosomal protein of 21 kDa (NEEP21). TI-VAMP/VAMP7 is essential for neuronal morphogenesis and mediates the vesicular transport processes underlying neurite outgrowth. Ykt6 is highly enriched in the cerebral cortex and hippocampus and is targeted to a novel compartment in neurons. Syntaxin 16 has a moderate expression level in many tissues, but is rather enriched in the brain. Here, we review and discuss the neuron-specific physiology and possible pathology of these and other (such as SNAP-29 and Vti1a-beta) members of the SNARE family.
Collapse
Affiliation(s)
- Ya Wang
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | | |
Collapse
|
87
|
Fejtova A, Davydova D, Bischof F, Lazarevic V, Altrock WD, Romorini S, Schöne C, Zuschratter W, Kreutz MR, Garner CC, Ziv NE, Gundelfinger ED. Dynein light chain regulates axonal trafficking and synaptic levels of Bassoon. ACTA ACUST UNITED AC 2009; 185:341-55. [PMID: 19380881 PMCID: PMC2700376 DOI: 10.1083/jcb.200807155] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Bassoon and the related protein Piccolo are core components of the presynaptic cytomatrix at the active zone of neurotransmitter release. They are transported on Golgi-derived membranous organelles, called Piccolo-Bassoon transport vesicles (PTVs), from the neuronal soma to distal axonal locations, where they participate in assembling new synapses. Despite their net anterograde transport, PTVs move in both directions within the axon. How PTVs are linked to retrograde motors and the functional significance of their bidirectional transport are unclear. In this study, we report the direct interaction of Bassoon with dynein light chains (DLCs) DLC1 and DLC2, which potentially link PTVs to dynein and myosin V motor complexes. We demonstrate that Bassoon functions as a cargo adapter for retrograde transport and that disruption of the Bassoon-DLC interactions leads to impaired trafficking of Bassoon in neurons and affects the distribution of Bassoon and Piccolo among synapses. These findings reveal a novel function for Bassoon in trafficking and synaptic delivery of active zone material.
Collapse
Affiliation(s)
- Anna Fejtova
- Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, D-39118 Magdeburg, Germany.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
88
|
Abstract
Proper synaptic function requires the seamless integration of the transport, assembly, and regulation of synaptic components and structures. Inasmuch as the synapse is often distant from the neuronal cell body, newly synthesized synaptic proteins, the precursors of synaptic vesicles, active zone compartments, channels and receptors, and mitochondria, must be transported along lengthy neuronal processes to participate in synaptogenesis. Neuronal transport is mediated by motor proteins that associate with their cargoes via adaptors (or receptors) and that travel along the cytoskeleton network within the neuronal processes. Thus, the identity of membranous protein cargoes and the specificity of motor-cargo interactions are critical for correctly targeting cargoes and properly assembling synapses in developing neurons and in remodeling synapses of mature neurons in response to neuronal activity. In this article, the authors review recent progress in characterizing microtubule- and actin-based motor proteins that are involved in delivering synaptic components and discuss potential mechanisms underlying the formation of motor-receptor-cargo complexes that contribute to synaptogenesis and activity-induced synaptic plasticity.
Collapse
Affiliation(s)
- Qian Cai
- Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | | |
Collapse
|
89
|
Brownhill K, Wood L, Allan V. Molecular motors and the Golgi complex: staying put and moving through. Semin Cell Dev Biol 2009; 20:784-92. [PMID: 19446479 DOI: 10.1016/j.semcdb.2009.03.019] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2009] [Revised: 03/30/2009] [Accepted: 03/31/2009] [Indexed: 11/19/2022]
Abstract
The Golgi apparatus is a highly dynamic organelle through which nascent proteins released from the endoplasmic reticulum (ER) are trafficked. Proteins are post-translationally modified within the Golgi and subsequently packaged into carriers for transport to a variety of cellular destinations. This transit of proteins, as well as the maintenance of Golgi structure and position, is highly dependent upon the actin and microtubule cytoskeletons and their associated molecular motors. Here we review how motors contribute to the correct functioning of the Golgi in higher eukaryotes and discuss the secretory pathway as a model system for studying cooperation between motor proteins.
Collapse
Affiliation(s)
- Kim Brownhill
- University of Manchester, Faculty of Life Sciences, The Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | | | | |
Collapse
|
90
|
Cai Q, Sheng ZH. Mitochondrial transport and docking in axons. Exp Neurol 2009; 218:257-67. [PMID: 19341731 DOI: 10.1016/j.expneurol.2009.03.024] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2008] [Revised: 03/16/2009] [Accepted: 03/18/2009] [Indexed: 01/06/2023]
Abstract
Proper transport and distribution of mitochondria in axons and at synapses are critical for the normal physiology of neurons. Mitochondria in axons display distinct motility patterns and undergo saltatory and bidirectional movement, where mitochondria frequently stop, start moving again, and change direction. While approximately one-third of axonal mitochondria are mobile in mature neurons, a large proportion remains stationary. Their net movement is significantly influenced by recruitment to stationary or motile states. In response to the diverse physiological states of axons and synapses, the mitochondrial balance between motile and stationary phases is a possible target of regulation by intracellular signals and synaptic activity. Efficient control of mitochondrial retention (docking) at particular stations, where energy production and calcium homeostasis capacity are highly demanded, is likely essential for neuronal development and function. In this review, we introduce the molecular and cellular mechanisms underlying the complex mobility patterns of axonal mitochondria and discuss how motor adaptor complexes and docking machinery contribute to mitochondrial transport and distribution in axons and at synapses. In addition, we briefly discuss the physiological evidence how axonal mitochondrial mobility impacts synaptic function.
Collapse
Affiliation(s)
- Qian Cai
- Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, USA.
| | | |
Collapse
|
91
|
MacAskill AF, Brickley K, Stephenson FA, Kittler JT. GTPase dependent recruitment of Grif-1 by Miro1 regulates mitochondrial trafficking in hippocampal neurons. Mol Cell Neurosci 2009; 40:301-12. [DOI: 10.1016/j.mcn.2008.10.016] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2008] [Revised: 10/28/2008] [Accepted: 10/31/2008] [Indexed: 11/16/2022] Open
|
92
|
Abstract
Mitochondrial dynamics and transport have emerged as key factors in the regulation of neuronal differentiation and survival. Mitochondria are dynamically transported in and out of axons and dendrites to maintain neuronal and synaptic function. Transport proceeds through a controlled series of plus- and minus-end directed movements along microtubule tracks (MTs) that are often interrupted by short stops. This bidirectional motility of mitochondria is facilitated by plus end-directed kinesin and minus end-directed dynein motors, and may be coordinated and controlled by a number of mechanisms that integrate intracellular signals to ensure efficient transport and targeting of mitochondria. In this chapter, we discuss our understanding of mechanisms that facilitate mitochondrial transport and delivery to specific target sites in dendrites and axons.
Collapse
|
93
|
Axonal transport and the delivery of pre-synaptic components. Curr Opin Neurobiol 2008; 18:495-503. [PMID: 18950710 DOI: 10.1016/j.conb.2008.10.003] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2008] [Revised: 09/30/2008] [Accepted: 10/05/2008] [Indexed: 12/30/2022]
Abstract
The mechanisms for delivering components to nerve terminals are diverse and highly regulated. The diversity of kinesin motors alone is insufficient to account for the specificity of delivery. Additional specificity and control are contributed by adaptor proteins and associated regulatory molecules. The interaction of cargos with these complexes can confer distinct behaviors on the transport of synaptic organelles. The rich regulatory mechanisms of transport that are only now emerging as the cargo-motor complexes are defined and subsequent local events that regulate their dynamic relationship are examined. Here we review recent studies of kinesin-related axonal transport of three crucial synaptic components, Piccolo-bassoon Transport Vesicles (PTVs), Synaptic Vesicle Precursors (SVPs), and mitochondria, and the mechanisms that modulate their transport.
Collapse
|
94
|
Seog DH, Han J. Sorting Nexin 17 Interacts Directly with Kinesin Superfamily KIF1Bbeta Protein. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2008; 12:199-204. [PMID: 19967056 DOI: 10.4196/kjpp.2008.12.4.199] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
KIF1Bbeta is a member of the Kinesin superfamily proteins (KIFs), which are microtubule-dependent molecular motors that are involved in various intracellular organellar transport processes. KIF1Bbeta is not restricted to neuronal systems, however, is widely expressed in other tissues, even though the function of KIF1Bbeta is still unclear. To elucidate the KIF1Bbeta-binding proteins in non-neuronal cells, we used the yeast two-hybrid system, and found a specific interaction of KIF1Bbeta and the sorting nexin (SNX) 17. The C-terminal region of SNX17 is required for the binding with KIF1Bbeta. SNX17 protein bound to the specific region of KIF1Bbeta (813-916. aa), but not to other kinesin family members. In addition, this specific interaction was also observed in the Glutathione S-transferase pull-down assay. An antibody to SNX17 specifically co-immunoprecipitated KIF1Bbeta associated with SNX17 from mouse brain extracts. These results suggest that SNX17 might be involved in the KIF1Bbeta-mediated transport as a KIF1Bbeta adaptor protein.
Collapse
Affiliation(s)
- Dae-Hyun Seog
- Department of Biochemistry, National Research Laboratory for Mitochondrial Signaling, College of Medicine, Cardiovascular and Metabolic Disease Center, Inje University, Busan 614-735, Korea
| | | |
Collapse
|
95
|
Soubannier V, McBride HM. Positioning mitochondrial plasticity within cellular signaling cascades. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2008; 1793:154-70. [PMID: 18694785 DOI: 10.1016/j.bbamcr.2008.07.008] [Citation(s) in RCA: 121] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2008] [Revised: 07/08/2008] [Accepted: 07/10/2008] [Indexed: 01/06/2023]
Abstract
Mitochondria evolved from alpha-proteobacteria captured within a host between two and three billion years ago. This origin resulted in the formation of a double-layered organelle resulting in four distinct sub-compartments: the outer membrane, the intermembrane space, the inner membrane and the matrix. The inner membrane is organized in cristae, harboring the respiratory chain and ATP synthase complexes responsible of the oxidative phosphorylation, the main energy-generating system of the cell. It is generally considered that the ultrastructure of the inner membrane provides a large variety of morphologies that facilitate metabolic output. This classical view of mitochondria as bean-shaped organelles was static until in the last decade when new imaging studies and genetic screens provided a more accurate description of a dynamic mitochondrial reticulum that fuse and divide continuously. Since then significant findings have been made in the study of machineries responsible for fusion, fission and motility, however the mechanisms and signals that regulate mitochondrial dynamics are only beginning to emerge. A growing body of evidence indicates that metabolic and cellular signals influence mitochondrial dynamics, leading to a new understanding of how changes in mitochondrial shape can have a profound impact on the functional output of the organelle. The mechanisms that regulate mitochondrial morphology are incompletely understood, but evidence to date suggests that the morphology machinery is modulated through the use of post-translational modifications, including nucleotide-binding proteins, phosphorylation, ubiquitination, SUMOylation, and changes in the lipid environment. This review focuses on the molecular switches that control mitochondrial dynamics and the integration of mitochondrial morphology within cellular signaling cascades.
Collapse
Affiliation(s)
- Vincent Soubannier
- University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON, Canada K1Y 4W7
| | | |
Collapse
|
96
|
Hirokawa N, Noda Y. Intracellular Transport and Kinesin Superfamily Proteins, KIFs: Structure, Function, and Dynamics. Physiol Rev 2008; 88:1089-118. [DOI: 10.1152/physrev.00023.2007] [Citation(s) in RCA: 345] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Various molecular cell biology and molecular genetic approaches have indicated significant roles for kinesin superfamily proteins (KIFs) in intracellular transport and have shown that they are critical for cellular morphogenesis, functioning, and survival. KIFs not only transport various membrane organelles, protein complexes, and mRNAs for the maintenance of basic cellular activity, but also play significant roles for various mechanisms fundamental for life, such as brain wiring, higher brain functions such as memory and learning and activity-dependent neuronal survival during brain development, and for the determination of important developmental processes such as left-right asymmetry formation and suppression of tumorigenesis. Accumulating data have revealed a molecular mechanism of cargo recognition involving scaffolding or adaptor protein complexes. Intramolecular folding and phosphorylation also regulate the binding activity of motor proteins. New techniques using molecular biophysics, cryoelectron microscopy, and X-ray crystallography have detected structural changes in motor proteins, synchronized with ATP hydrolysis cycles, leading to the development of independent models of monomer and dimer motors for processive movement along microtubules.
Collapse
|
97
|
Kang JS, Tian JH, Pan PY, Zald P, Li C, Deng C, Sheng ZH. Docking of axonal mitochondria by syntaphilin controls their mobility and affects short-term facilitation. Cell 2008; 132:137-48. [PMID: 18191227 DOI: 10.1016/j.cell.2007.11.024] [Citation(s) in RCA: 436] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2007] [Revised: 07/17/2007] [Accepted: 11/09/2007] [Indexed: 01/20/2023]
Abstract
Proper distribution of mitochondria within axons and at synapses is critical for neuronal function. While one-third of axonal mitochondria are mobile, a large proportion remains in a stationary phase. However, the mechanisms controlling mitochondrial docking within axons remain elusive. Here, we report a role for axon-targeted syntaphilin (SNPH) in mitochondrial docking through its interaction with microtubules. Axonal mitochondria that contain exogenously or endogenously expressed SNPH lose mobility. Deletion of the mouse snph gene results in a substantially higher proportion of axonal mitochondria in the mobile state and reduces the density of mitochondria in axons. The snph mutant neurons exhibit enhanced short-term facilitation during prolonged stimulation, probably by affecting calcium signaling at presynaptic boutons. This phenotype is fully rescued by reintroducing the snph gene into the mutant neurons. These findings demonstrate a molecular mechanism for controlling mitochondrial docking in axons that has a physiological impact on synaptic function.
Collapse
Affiliation(s)
- Jian-Sheng Kang
- Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Building 35, Room 3B203, 35 Convent Drive, Bethesda, MD 20892, USA
| | | | | | | | | | | | | |
Collapse
|
98
|
Boldogh IR, Pon LA. Mitochondria on the move. Trends Cell Biol 2007; 17:502-10. [PMID: 17804238 DOI: 10.1016/j.tcb.2007.07.008] [Citation(s) in RCA: 196] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2007] [Revised: 07/01/2007] [Accepted: 07/24/2007] [Indexed: 12/21/2022]
Abstract
Interactions of mitochondria with the cytoskeleton are crucial for normal mitochondrial function and for localization of the organelle at its sites of action within cells. Early studies revealed a role for microtubule motors in mitochondrial motility in neurons and other cell types. Here, we describe advances in our understanding of mitochondrial movement and distribution. Specifically, we review recent studies on proteins that mediate or regulate the interaction between motor molecules and the organelle, motor-independent mechanisms for mitochondrial motility, anchorage of mitochondria at cortical sites within cells and links between mitochondria-cytoskeleton interactions and mitochondrial plasticity.
Collapse
Affiliation(s)
- Istvan R Boldogh
- Department of Anatomy and Cell Biology, Columbia University, College of Physicians and Surgeons, 1130 St. Nicholas Avenue, Room 311B, New York, NY 10032, USA
| | | |
Collapse
|
99
|
Cai Q, Pan PY, Sheng ZH. Syntabulin-kinesin-1 family member 5B-mediated axonal transport contributes to activity-dependent presynaptic assembly. J Neurosci 2007; 27:7284-96. [PMID: 17611281 PMCID: PMC6794594 DOI: 10.1523/jneurosci.0731-07.2007] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The mechanism by which microtubule-based axonal transport regulates activity-dependent presynaptic plasticity in developing neurons remains mostly unknown. Our previous studies established that syntabulin is an adaptor capable of conjoining the kinesin family member 5B (KIF5B) motor and syntaxin-1. We now report that the complex of syntaxin-1-syntabulin-KIF5B mediates axonal transport of the active zone (AZ) components essential for presynaptic assembly. Syntabulin associates with AZ precursor carriers and colocalizes and comigrates with green fluorescent protein (GFP)-Bassoon-labeled AZ transport cargos within developing axons. Knock-down of syntabulin or disruption of the syntaxin-1-syntabulin-KIF5B complex impairs the anterograde transport of GFP-Bassoon out of the soma and reduces the axonal densities of synaptic vesicle (SV) clusters and FM4-64 [N-(3-triethylammoniumpropyl)-4-(p-dibutylaminostyryl)pyridinium, dibromide] loading. Furthermore, syntabulin loss of function results in a reduction in both the amplitude of postsynaptic currents and the frequency of asynchronous quantal events, and abolishes the activity-induced recruitment of new GFP-Bassoon into the axons and subsequent coclustering with SVs. Consequently, syntabulin loss of function blocks the formation of new presynaptic boutons during activity-dependent synaptic plasticity in developing neurons. These studies establish that a kinesin motor-adaptor complex is critical for the anterograde axonal transport of AZ components, thus contributing to activity-dependent presynaptic assembly during neuronal development.
Collapse
Affiliation(s)
- Qian Cai
- Synaptic Function Unit, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892-3701
| | - Ping-Yue Pan
- Synaptic Function Unit, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892-3701
| | - Zu-Hang Sheng
- Synaptic Function Unit, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892-3701
| |
Collapse
|
100
|
Bracale A, Cesca F, Neubrand VE, Newsome TP, Way M, Schiavo G. Kidins220/ARMS is transported by a kinesin-1-based mechanism likely to be involved in neuronal differentiation. Mol Biol Cell 2006; 18:142-52. [PMID: 17079733 PMCID: PMC1751333 DOI: 10.1091/mbc.e06-05-0453] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Kinase D-interacting substrate of 220 kDa/ankyrin repeat-rich membrane spanning (Kidins220/ARMS) is a conserved membrane protein mainly expressed in brain and neuroendocrine cells, which is a downstream target of the signaling cascades initiated by neurotrophins and ephrins. We identified kinesin light chain 1 (KLC1) as a binding partner for Kidins220/ARMS by a yeast two-hybrid screen. The interaction between Kidins220/ARMS and the kinesin-1 motor complex was confirmed by glutathione S-transferase-pull-down and coimmunoprecipitation experiments. In addition, Kidins220/ARMS and kinesin-1 were shown to colocalize in nerve growth factor (NGF)-differentiated PC12 cells. Using Kidins220/ARMS and KLC1 mutants, we mapped the regions responsible for the binding to a short sequence of Kidins220/ARMS, termed KLC-interacting motif (KIM), which is sufficient for the interaction with KLC1. Optimal binding of KIM requires a region of KLC1 spanning both the tetratricopeptide repeats and the heptad repeats, previously not involved in cargo recognition. Overexpression of KIM in differentiating PC12 cells impairs the formation and transport of EGFP-Kidins220/ARMS carriers to the tips of growing neurites, leaving other kinesin-1 dependent processes unaffected. Furthermore, KIM overexpression interferes with the activation of the mitogen-activated protein kinase signaling and neurite outgrowth in NGF-treated PC12 cells. Our results suggest that Kidins220/ARMS-positive carriers undergo a kinesin-1-dependent transport linked to neurotrophin action.
Collapse
Affiliation(s)
| | | | | | - Timothy P. Newsome
- Cell Motility Laboratories, Cancer Research UK London Research Institute, London WC2A 3PX, United Kingdom
| | - Michael Way
- Cell Motility Laboratories, Cancer Research UK London Research Institute, London WC2A 3PX, United Kingdom
| | | |
Collapse
|