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Mizukami M, Kanamoto T, Souchelnytskyi N, Kiuchi Y. Proteome profiling of embryo chick retina. Proteome Sci 2008; 6:3. [PMID: 18208622 PMCID: PMC2267454 DOI: 10.1186/1477-5956-6-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2007] [Accepted: 01/22/2008] [Indexed: 12/23/2022] Open
Abstract
Background Little is known regarding the molecular pathways that underlie the process of retinal development. The purpose of this study was to identify proteins which may be involved in development of retina. We used a proteomics-based approach to identify proteins that are up- or down-regulated during the development of the embryo chick retina. Results Two-dimensional gel electrophoresis was performed with the retina of embryo chicken, which was obtained from embryos of day 7 (ED7) and of day 11 (ED11). The protein spots showing significant differences were selected for identification by MALDI mass spectrometry. Thirteen proteins were differentially expressed; seven proteins were up-regulated in embryo retina of chicken at ED 11 and six proteins were down-regulated. Significant proteins were also evaluated in embryo day 15 (ED15). Some of identified proteins were known to regulate cell proliferation, cell death, transport, metabolism, organization and extracellular matrix, and others also included novel proteins. Conclusion We identified thirteen proteins which differentially expressed in embryonal retina of chicken at day 7, as compared to the retina of embryo of day 11. They were various regulatory proteins for cellular signaling.
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Affiliation(s)
- Mina Mizukami
- Department of Ophthalmology and Visual Science, Hiroshima University, Japan.
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3
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Hunter AW, Caplow M, Coy DL, Hancock WO, Diez S, Wordeman L, Howard J. The kinesin-related protein MCAK is a microtubule depolymerase that forms an ATP-hydrolyzing complex at microtubule ends. Mol Cell 2003; 11:445-57. [PMID: 12620232 PMCID: PMC6468321 DOI: 10.1016/s1097-2765(03)00049-2] [Citation(s) in RCA: 275] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
MCAK belongs to the Kin I subfamily of kinesin-related proteins, a unique group of motor proteins that are not motile but instead destabilize microtubules. We show that MCAK is an ATPase that catalytically depolymerizes microtubules by accelerating, 100-fold, the rate of dissociation of tubulin from microtubule ends. MCAK has one high-affinity binding site per protofilament end, which, when occupied, has both the depolymerase and ATPase activities. MCAK targets protofilament ends very rapidly (on-rate 54 micro M(-1).s(-1)), perhaps by diffusion along the microtubule lattice, and, once there, removes approximately 20 tubulin dimers at a rate of 1 s(-1). We propose that up to 14 MCAK dimers assemble at the end of a microtubule to form an ATP-hydrolyzing complex that processively depolymerizes the microtubule.
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Affiliation(s)
- Andrew W. Hunter
- Department of Physiology and Biophysics, University of Washington Seattle, Washington 98195
- Present address: Department of Cell Biology and Anatomy, Medical University of South Carolina, 173 Ashley Avenue, P.O. Box 250508, Charleston, South Carolina 29425
| | - Michael Caplow
- Department of Biochemistry and Biophysics, University of North Carolina Medical School, Chapel Hill, North Carolina 27599
| | - David L. Coy
- Department of Physiology and Biophysics, University of Washington Seattle, Washington 98195
| | - William O. Hancock
- Department of Bioengineering, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Stefan Diez
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Linda Wordeman
- Department of Physiology and Biophysics, University of Washington Seattle, Washington 98195
| | - Jonathon Howard
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
- Correspondence:
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Cai Y, Singh BB, Aslanukov A, Zhao H, Ferreira PA. The docking of kinesins, KIF5B and KIF5C, to Ran-binding protein 2 (RanBP2) is mediated via a novel RanBP2 domain. J Biol Chem 2001; 276:41594-602. [PMID: 11553612 DOI: 10.1074/jbc.m104514200] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Ran-binding protein 2 (RanBP2) is a vertebrate mosaic protein composed of four interspersed RanGTPase binding domains (RBDs), a variable and species-specific zinc finger cluster domain, leucine-rich, cyclophilin, and cyclophilin-like (CLD) domains. Functional mapping of RanBP2 showed that the domains, zinc finger and CLD, between RBD1 and RBD2, and RBD3 and RBD4, respectively, associate specifically with the nuclear export receptor, CRM1/exportin-1, and components of the 19 S regulatory particle of the 26 S proteasome. Now, we report the mapping of a novel RanBP2 domain located between RBD2 and RBD3, which is also conserved in the partially duplicated isoform RanBP2L1. Yet, this domain leads to the neuronal association of only RanBP2 with two kinesin microtubule-based motor proteins, KIF5B and KIF5C. These kinesins associate directly in vitro and in vivo with RanBP2. Moreover, the kinesin light chain and RanGTPase are part of this RanBP2 macroassembly complex. These data provide evidence of a specific docking site in RanBP2 for KIF5B and KIF5C. A model emerges whereby RanBP2 acts as a selective signal integrator of nuclear and cytoplasmic trafficking pathways in neurons.
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Affiliation(s)
- Y Cai
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
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5
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Noda Y, Okada Y, Saito N, Setou M, Xu Y, Zhang Z, Hirokawa N. KIFC3, a microtubule minus end-directed motor for the apical transport of annexin XIIIb-associated Triton-insoluble membranes. J Cell Biol 2001; 155:77-88. [PMID: 11581287 PMCID: PMC2150803 DOI: 10.1083/jcb.200108042] [Citation(s) in RCA: 132] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We have identified and characterized a COOH-terminal motor domain-type kinesin superfamily protein (KIFC), KIFC3, in the kidney. KIFC3 is a minus end-directed microtubule motor protein, therefore it accumulates in regions where minus ends of microtubules assemble. In polarized epithelial cells, KIFC3 is localized on membrane organelles immediately beneath the apical plasma membrane of renal tubular epithelial cells in vivo and polarized MDCK II cells in vitro. Flotation assay, coupled with detergent extraction, demonstrated that KIFC3 is associated with Triton X-100-insoluble membrane organelles, and that it overlaps with apically transported TGN-derived vesicles. This was confirmed by immunoprecipitation and by GST pulldown experiments showing the specific colocalization of KIFC3 and annexin XIIIb, a previously characterized membrane protein for apically transported vesicles (Lafont, F., S. Lecat, P. Verkade, and K. Simons. 1998. J. Cell Biol. 142:1413-1427). Furthermore, we proved that the apical transport of both influenza hemagglutinin and annexin XIIIb was partially inhibited or accelerated by overexpression of motor-domainless (dominant negative) or full-length KIFC3, respectively. Absence of cytoplasmic dynein on these annexin XIIIb-associated vesicles and distinct distribution of the two motors on the EM level verified the existence of KIFC3-driven transport in epithelial cells.
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Affiliation(s)
- Y Noda
- Department of Cell Biology and Anatomy, Graduate School of Medicine, University of Tokyo, Hongo, Tokyo 113-0033, Japan
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6
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Abstract
Molecular motors that hydrolyze ATP and use the derived energy to generate force are involved in a variety of diverse cellular functions. Genetic, biochemical, and cellular localization data have implicated motors in a variety of functions such as vesicle and organelle transport, cytoskeleton dynamics, morphogenesis, polarized growth, cell movements, spindle formation, chromosome movement, nuclear fusion, and signal transduction. In non-plant systems three families of molecular motors (kinesins, dyneins, and myosins) have been well characterized. These motors use microtubules (in the case of kinesines and dyneins) or actin filaments (in the case of myosins) as tracks to transport cargo materials intracellularly. During the last decade tremendous progress has been made in understanding the structure and function of various motors in animals. These studies are yielding interesting insights into the functions of molecular motors and the origin of different families of motors. Furthermore, the paradigm that motors bind cargo and move along cytoskeletal tracks does not explain the functions of some of the motors. Relatively little is known about the molecular motors and their roles in plants. In recent years, by using biochemical, cell biological, molecular, and genetic approaches a few molecular motors have been isolated and characterized from plants. These studies indicate that some of the motors in plants have novel features and regulatory mechanisms. The role of molecular motors in plant cell division, cell expansion, cytoplasmic streaming, cell-to-cell communication, membrane trafficking, and morphogenesis is beginning to be understood. Analyses of the Arabidopsis genome sequence database (51% of genome) with conserved motor domains of kinesin and myosin families indicates the presence of a large number (about 40) of molecular motors and the functions of many of these motors remain to be discovered. It is likely that many more motors with novel regulatory mechanisms that perform plant-specific functions are yet to be discovered. Although the identification of motors in plants, especially in Arabidopsis, is progressing at a rapid pace because of the ongoing plant genome sequencing projects, only a few plant motors have been characterized in any detail. Elucidation of function and regulation of this multitude of motors in a given species is going to be a challenging and exciting area of research in plant cell biology. Structural features of some plant motors suggest calcium, through calmodulin, is likely to play a key role in regulating the function of both microtubule- and actin-based motors in plants.
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Affiliation(s)
- A S Reddy
- Department of Biology and Program in Cell and Molecular Biology, Colorado State University, Fort Collins 80523, USA
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7
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Abstract
Most UNC-104/KIF1 kinesins are monomeric motors that transport membrane-bounded organelles toward the plus ends of microtubules. Recent evidence implies that KIF1A, a synaptic vesicle motor, moves processively. This surprising behavior for a monomeric motor depends upon a lysine-rich loop in KIF1A that binds to the negatively charged carboxyl terminus of tubulin and, in the context of motor processivity, compensates for the lack of a second motor domain on the KIF1A holoenzyme.
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Affiliation(s)
- G S Bloom
- University of Virginia, Department of Biology, Gilmer Hall, Room 229, Charlottesville, Virginia 22903, USA.
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8
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Abstract
Kinesin superfamily proteins (KIFs) are the molecular motors conveying cargos along microtubules. KIF5s, the heavy chains of conventional kinesin (KHC), are originally identified members of KIFs, and neuronal KIF5A and ubiquitous KIF5B have been identified so far. In the present work, we cloned a novel member of KIF5, KIF5C, and generated specific antibodies against three KIF5s to investigate their distribution and functions. KIF5A showed pan-neuronal distribution in the nervous system. KIF5B showed a glial cell distribution pattern in general; however, interestingly, its expression was strongly upregulated in axon-elongating neurons, such as olfactory primary neurons and mossy fibers. KIF5C was also a neuronal KIF5 like KIF5A but was highly expressed in lower motor neurons in 2-week-old or older mice, suggesting its important roles in the maintenance of motor neurons rather than in their formation, such as axonal elongation. Because a large part of KIF5s in adult motor neurons were expected to be KIF5C, we generated mice lacking the kif5C gene to investigate the functions of KIF5C in neurons in living animals. The mutant mice showed smaller brain size but were viable and did not show gross changes in the nervous system. Closer examinations revealed the relative loss of motor neurons to sensory neurons. Because three KIF5s showed high similarity in the amino acid sequence, could rescue the KIF5B mutant cells, and could form heterodimers, we think that there are functional redundancy among the three KIF5s and that KIF5A and KIF5B prevented the KIF5C null mice from the severe phenotype.
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Zhiyong MA, Khatlani TS, Sasaki K, Inokuma H, Onishi T. Cloning of canine cDNA encoding tektin. J Vet Med Sci 2000; 62:1013-6. [PMID: 11039601 DOI: 10.1292/jvms.62.1013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Tektins are a group of proteins that form filamentous polymers in the walls of ciliary microtubules. The cloning of canine cDNA encoding tektin, was carried out and identified from the testis of beagle dog. Canine tektin cDNA is 1,523 bp in length, has an open reading frame of 1,281 bp nucleotides encoding a protein of 426 deduced amino acids. The predicted amino acid sequence has 77% and 33-50% of homology with the murine tektin and the sea urchin tektins. The amino acid sequence RPNVELCRD and four cysteine residues were conserved in the dog, mouse and sea urchin, suggesting the functional significance of this protein domain and the amino acid residues in the tektin proteins.
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Affiliation(s)
- M A Zhiyong
- Laboratory of Veterinary Internal Medicine, Faculty of Agriculture, Yamaguchi University, Yoshida, Japan
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10
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King-Smith C, Paz P, Lee CW, Lam W, Burnside B. Bidirectional pigment granule migration in isolated retinal pigment epithelial cells requires actin but not microtubules. CELL MOTILITY AND THE CYTOSKELETON 2000; 38:229-49. [PMID: 9384214 DOI: 10.1002/(sici)1097-0169(1997)38:3<229::aid-cm2>3.0.co;2-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In the teleost retinal pigment epithelium (RPE), melanin pigment granules disperse into long apical projections in the light and reaggregate into the cell body in the dark. To investigate the cytoskeletal mechanisms responsible for these movements, we have examined the effects of cytoskeletal inhibitors on pigment granule transport in cultured, dissociated RPE cells using time-lapse video microscopy. The kinetics of pigment granule transport during normal aggregation and dispersion are quite distinct: during aggregation, all pigment granules undergo simultaneous, nonsaltatory centripetal movement (mean velocity 3.6 microm/min); during dispersion, individual granules undergo independent, bidirectional saltatations (mean velocities 3.7 microm/min centrifugal; 1.1 microm/min centripetal). Nocodazole disruption of microtubules within the RPE apical projections had little effect on the kinetics of pigment granule movement, and essentially no effect on extent of pigment granule aggregation or dispersion, or on maintenance of the fully aggregated or fully dispersed states. In contrast, cytochalasin D (CD) treatment blocked net aggregation and dispersion of pigment granules, and compromised maintenance of the fully aggregated and dispersed states. These observations suggest that the actin cytoskeleton plays an important role in both centripetal and centrifugal transport of pigment granules in teleost RPE cells.
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Affiliation(s)
- C King-Smith
- Department of Molecular and Cell Biology, University of California, Berkeley 94720-3200, USA
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Sung CH, Tai AW. Rhodopsin trafficking and its role in retinal dystrophies. INTERNATIONAL REVIEW OF CYTOLOGY 1999; 195:215-67. [PMID: 10603577 DOI: 10.1016/s0074-7696(08)62706-0] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
We review the sorting/targeting steps involved in the delivery of rhodopsin to the outer segment compartment of highly polarized photoreceptor cells. The transport of rhodopsin includes (1) the sorting/budding of rhodopsin-containing vesicles at the trans-Golgi network, (2) the directional translocation of rhodopsin-bearing vesicles through the inner segment, and (3) the delivery of rhodopsin across the connecting cilium to the outer segment. Several independent lines of evidence suggest that the carboxyl-terminal, cytoplasmic tail of rhodopsin is involved in the post-Golgi trafficking of rhodopsin. Inappropriate subcellular targeting of naturally occurring rhodopsin mutants in vivo leads to photoreceptor cell death. Thus, the genes encoding mutations in the cellular components involved in photoreceptor protein transport are likely candidate genes for retinal dystrophies.
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Affiliation(s)
- C H Sung
- Department of Cell Biology and Anatomy, Margaret M. Dyson Vision Research Institute, Weill Medical College of Cornell University, New York, New York 10021, USA.
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12
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Whitehead JL, Wang SY, Bost-Usinger L, Hoang E, Frazer KA, Burnside B. Photoreceptor localization of the KIF3A and KIF3B subunits of the heterotrimeric microtubule motor kinesin II in vertebrate retina. Exp Eye Res 1999; 69:491-503. [PMID: 10548469 DOI: 10.1006/exer.1999.0724] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The heterotrimeric microtubule motor kinesin II has been shown to be required for morphogenesis and maintenance of both motile flagella and immotile sensory cilia. Recently, we showed that the KIF3A subunit of kinesin II is concentrated in the inner segment and connecting cilium of fish photoreceptors. Here we report the gene structure of human KIF3A (HsKIF3A) and describe its localization in human and monkey retina. We also describe the localization of both KIF3A and KIF3B kinesin II subunits in Xenopus retina. Using a portion of HsKIF3A we had amplified from adult human retinal cDNA, we found by a GenBank database search that an identical sequence had already been obtained by the Human Genome Center at Lawrence Berkeley National Laboratories in a direct sequencing analysis of 680 kb of human chromosome 5q31. By comparing the genomic sequence of HsKIF3A to the open reading frame (ORF) of the highly homologous mouse Kif3A, we determined that the HsKIF3A gene has 17 exons and an ORF of approximately 2.1 kb, predicting a protein of 80.3 kDa. Antibodies against sea urchin KRP85, a KIF3A homologue, bound to a single band of approximately 85 kDa in immunoblots of total retina protein from human, monkey and Xenopus. In these same samples, a single band of approximately 95 kDa is recognized by antibodies against Xklp3, a Xenopus KIF3B homologue. In sections of Xenopus retina, both antibodies strongly labelled photoreceptor inner segments and the outer limiting membrane. Both antibodies also labelled photoreceptor axonemes. The axonemal localization of kinesin II subunits suggests that kinesin II may play a role in transport of materials from the photoreceptor cell body to the outer segment.
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Affiliation(s)
- J L Whitehead
- Department of Molecular and Cell Biology, University of California, 335 Life Sciences Addition, Berkeley, CA, 94720-3200, USA
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13
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Gong TW, Winnicki RS, Kohrman DC, Lomax MI. A novel mouse kinesin of the UNC-104/KIF1 subfamily encoded by the Kif1b gene. Gene 1999; 239:117-27. [PMID: 10571041 DOI: 10.1016/s0378-1119(99)00370-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Kinesin and kinesin-related proteins are microtubule-dependent motor proteins that transport organelles. We have cloned and sequenced a full-length 9924 bp mouse cDNA for a new kinesin of the UNC-104/KIF1 subfamily. Northern blot analysis of mouse RNAs detected high levels of a 10 kb mRNA in brain and eye, but lower levels in other tissues. Human RNA dot-blot analysis detected this mRNA in all tissues examined, although at different levels. The overall structure of the new kinesin (predicted size 204 kDa) was most similar to mouse KIF1A; however, 2.1 kb of the 5' portion of the cDNA were identical to the published sequence for KIF1B (Nangaku, M., Sato-Yoshitake, R., Okada, Y., Noda, Y., Takemura, R., Yamazaki, H., Hirokawa, N., 1994. KIF1B, a novel microtubule plus end-directed monomeric motor protein for transport of mitochondria. Cell 79, 1209-1220). We localized the Kif1b gene to the distal end of mouse Chromosome 4 by haplotype analysis of an interspecific backcross from The Jackson Laboratory. We had previously mapped the gene for the novel kinesin to the same location (Gong, T.-W.L., Burmeister, M., Lomax, M.I., 1996b. The novel gene D4Mille maps to mouse Chromosome 4 and human Chromosome 1p36. Mamm. Genome 7, 790-791). We conclude, therefore, that the Kif1b gene generates two major kinesin isoforms by alternative splicing. The shorter 7.8 kb mRNA encodes a 130 kDa kinesin, KIF1Bp130, whereas the 10 kb mRNA encodes a 204 kDa kinesin, KIF1Bp204. In addition, alternative splicing of two exons in the conserved region adjacent to the motor domain generates four different isoforms of each kinesin, leading to eight kinesin isoforms derived from the Kif1b gene.
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Affiliation(s)
- T W Gong
- Kresge Hearing Research Institute, Department of Otolaryngology/Head Neck Surgery, University of Michigan, Ann Arbor 48109, USA
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Hoang E, Bost-Usinger L, Burnside B. Characterization of a novel C-kinesin (KIFC3) abundantly expressed in vertebrate retina and RPE. Exp Eye Res 1999; 69:57-68. [PMID: 10375449 DOI: 10.1006/exer.1999.0671] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Many forms of intracellular transport are mediated by microtubule-dependent motors of the kinesin superfamily (KIFs). To identify kinesins expressed in human retina and RPE, we used degenerate primer RT-PCR to amplify a approximately 440 bp kinesin motor domain fragment from human retinal and RPE messenger RNAs. Four distinct kinesins were detected: one C-kinesin (HsKIFC3); one kinesin from the unc104/KIF1 family [HsKIF1A]; and the ubiquitous and neuronal forms of conventional kinesin heavy chain [HsuKHC and HsnKHC]. The C-kinesin HsKIFC3 comprised 33.3% of the retinal clones and was 60% identical to FKIF2, the most abundant kinesin detected in a previous screen of fish retina and 95% identical to a fragment of MmKifC3 recently amplified from mouse brain. Elsewhere we have reported the sequence of HsKIFC3 and shown that it maps to the same locus on chromosome 16q13-q21 as Bardet-Biedl syndrome Type II, a hereditary retinal degeneration. We describe here the kinesin PCR screen of human retina and RPE and examine the tissue and subcellular distribution of KIFC3 in both fish and human retina using an antibody raised against a peptide conserved between FKIF2 and HsKIFC3. This peptide antibody identified a single approximately 80 kDa band in Western blots of fish and human retina and RPE. In both fish and human retina this antibody strongly labeled photoreceptor terminals in the outer plexiform layer, suggesting that FKIF2/KIFC3 may play some role in the photoreceptor synapse.
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Affiliation(s)
- E Hoang
- Department of Molecular and Cell Biology, University of California, 335 Life Sciences Addition, Berkeley, CA, 94720-3200, USA
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Abstract
Many types of neural tissues and sensory cells possess either motile or primary cilia. We report the first mammalian (murine testis) cDNA for tektin, a protein unique to cilia, flagella, and centrioles, which we have used to identify related proteins and genes in sensory tissues. Comparison with the sequence database reveals that tektins are a gene family, spanning evolution from Caenorhabditis elegans (in which they correlate with touch receptor cilia) and Drosophila melanogaster, to Mus musculus and Homo sapiens (in which they are found in brain, retina, melanocytes, and at least 13 other tissues). The peptide sequence RPNVELCRD, or a variant of it, is a prominent feature of tektins and is likely to form a functionally important protein domain. Using the cDNA as a probe, we determined the onset, relative levels, and locations of tektin expression in mouse for several adult tissues and embryonic stages by Northern blot analysis and in situ hybridization. Tektin expression is significant in adult brain and in the choroid plexus, the forming retina (primitive ependymal zone corresponding to early differentiating photoreceptor cells), and olfactory receptor neurons of stage embryonic day 14 embryos. There is a striking correlation of tektin expression with the known presence of either motile or primary cilia. The evolutionary conservation of tektins and their association with tubulin in cilia and centriole formation make them important and useful molecular targets for the study of neural development.
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Hoang EH, Whitehead JL, Dosé AC, Burnside B. Cloning of a novel C-terminal kinesin (KIFC3) that maps to human chromosome 16q13-q21 and thus is a candidate gene for Bardet-Biedl syndrome. Genomics 1998; 52:219-22. [PMID: 9782090 DOI: 10.1006/geno.1998.5431] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Kinesins are a large superfamily of microtubule motors that mediate specific motile processes. In a previous study, we identified 11 kinesin family members in the retina and retinal pigment epithelium (RPE) of the striped bass, Morone saxatilus. We have now identified, cloned, and sequenced the human homologue (KIFC3) of the most abundantly expressed retinal kinesin from that study, the C-terminal kinesin FKIF2. An antibody raised against an FKIF2 peptide cross-reacted with an approximately 80-kDa protein in human retina, RPE, kidney, and lung. Since microtubule-dependent processes are critical to the function and morphogenesis of the photoreceptors and RPE, the abundantly expressed KIFC3 was considered to be a potential candidate gene for causing human retinal degeneration. Chromosomal localization of the KIFC3 gene revealed that it maps to chromosome 16q13-q21, within the critical region for a Bardet-Biedl syndrome locus (BBS2). Bardet-Biedl syndrome is a genetically heterogeneous, autosomal recessive disorder characterized by retinal dystrophy, polydactyly, obesity, hypogonadism, renal abnormalities, and mental retardation. The chromosomal localization and expression pattern of KIFC3 suggest that it may be an excellent candidate for families linked to BBS2.
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Affiliation(s)
- E H Hoang
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California, 94720, USA
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Tanaka Y, Kanai Y, Okada Y, Nonaka S, Takeda S, Harada A, Hirokawa N. Targeted disruption of mouse conventional kinesin heavy chain, kif5B, results in abnormal perinuclear clustering of mitochondria. Cell 1998; 93:1147-58. [PMID: 9657148 DOI: 10.1016/s0092-8674(00)81459-2] [Citation(s) in RCA: 476] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Mouse kif5B gene was disrupted by homologous recombination. kif5B-/- mice were embryonic lethal with a severe growth retardation at 9.5-11.5 days postcoitum. To analyze the significance of this conventional kinesin heavy chain in organelle transport, we studied the distribution of major organelles in the extraembryonic cells. The null mutant cells impaired lysosomal dispersion, while brefeldin A could normally induce the breakdown of their Golgi apparatus. More prominently, their mitochondria abnormally clustered in the perinuclear region. This mitochondrial phenotype was reversed by an exogenous expression of KIF5B, and a subcellular fractionation revealed that KIF5B is associated with mitochondria. These data collectively indicate that kinesin is essential for mitochondrial and lysosomal dispersion rather than for the Golgi-to-ER traffic in these cells.
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Affiliation(s)
- Y Tanaka
- Department of Cell Biology and Anatomy, Graduate School of Medicine, University of Tokyo, Hongo, Japan
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