scholarly journals A Dynein Light Chain Is Essential for the Retrograde Particle Movement of Intraflagellar Transport (IFT)

1998 ◽  
Vol 141 (4) ◽  
pp. 979-992 ◽  
Author(s):  
Gregory J. Pazour ◽  
Curtis G. Wilkerson ◽  
George B. Witman

Several enzymes, including cytoplasmic and flagellar outer arm dynein, share an Mr 8,000 light chain termed LC8. The function of this chain is unknown, but it is highly conserved between a wide variety of organisms. We have identified deletion alleles of the gene (fla14) encoding this protein in Chlamydomonas reinhardtii. These mutants have short, immotile flagella with deficiencies in radial spokes, in the inner and outer arms, and in the beak-like projections in the B tubule of the outer doublet microtubules. Most dramatically, the space between the doublet microtubules and the flagellar membrane contains an unusually high number of rafts, the particles translocated by intraflagellar transport (IFT) (Kozminski, K.G., P.L. Beech, and J.L. Rosenbaum. 1995. J. Cell Biol. 131:1517–1527). IFT is a rapid bidirectional movement of rafts under the flagellar membrane along axonemal microtubules. Anterograde IFT is dependent on a kinesin whereas the motor for retrograde IFT is unknown. Anterograde IFT is normal in the LC8 mutants but retrograde IFT is absent; this undoubtedly accounts for the accumulation of rafts in the flagellum. This is the first mutation shown to specifically affect retrograde IFT; the fact that LC8 loss affects retrograde IFT strongly suggests that cytoplasmic dynein is the motor that drives this process. Concomitant with the accumulation of rafts, LC8 mutants accumulate proteins that are components of the 15-16S IFT complexes (Cole, D.G., D.R. Deiner, A.L. Himelblau, P.L. Beech, J.C. Fuster, and J.L. Rosenbaum. 1998. J. Cell Biol. 141:993–1008), confirming that these complexes are subunits of the rafts. Polystyrene microbeads are still translocated on the surface of the flagella of LC8 mutants, indicating that the motor for flagellar surface motility is different than the motor for retrograde IFT.

1995 ◽  
Vol 131 (6) ◽  
pp. 1517-1527 ◽  
Author(s):  
K G Kozminski ◽  
P L Beech ◽  
J L Rosenbaum

The Chlamydomonas FLA10 gene was shown to encode a flagellar kinesin-like protein (Walther, Z., M. Vashishtha, and J.L. Hall. 1994. J. Cell Biol. 126:175-188). By using a temperature-sensitive allele of FLA10, we have determined that the FLA10 protein is necessary for both the bidirectional movement of polystyrene beads on the flagellar membrane and intraflagellar transport (IFT), the bidirectional movement of granule-like particles beneath the flagellar membrane (Kozminski, K.G., K.A. Johnson, P. Forscher, and J.L. Rosenbaum. 1993. Proc. Natl. Acad. Sci. (USA). 90:5519-5523). In addition, we have correlated the presence and position of the IFT particles visualized by light microscopy with that of the electron dense complexes (rafts) observed beneath the flagellar membrane by electron microscopy. A role for FLA10 in submembranous or flagellar surface motility is also strongly supported by the immunolocalization of FLA10 to the region between the axonemal outer doublet microtubules and the flagellar membrane.


2011 ◽  
Vol 22 (15) ◽  
pp. 2690-2701 ◽  
Author(s):  
Melissa D. Stuchell-Brereton ◽  
Amanda Siglin ◽  
Jun Li ◽  
Jeffrey K. Moore ◽  
Shubbir Ahmed ◽  
...  

Cytoplasmic dynein is a large multisubunit complex involved in retrograde transport and the positioning of various organelles. Dynein light chain (LC) subunits are conserved across species; however, the molecular contribution of LCs to dynein function remains controversial. One model suggests that LCs act as cargo-binding scaffolds. Alternatively, LCs are proposed to stabilize the intermediate chains (ICs) of the dynein complex. To examine the role of LCs in dynein function, we used Saccharomyces cerevisiae, in which the sole function of dynein is to position the spindle during mitosis. We report that the LC8 homologue, Dyn2, localizes with the dynein complex at microtubule ends and interacts directly with the yeast IC, Pac11. We identify two Dyn2-binding sites in Pac11 that exert differential effects on Dyn2-binding and dynein function. Mutations disrupting Dyn2 elicit a partial loss-of-dynein phenotype and impair the recruitment of the dynein activator complex, dynactin. Together these results indicate that the dynein-based function of Dyn2 is via its interaction with the dynein IC and that this interaction is important for the interaction of dynein and dynactin. In addition, these data provide the first direct evidence that LC occupancy in the dynein motor complex is important for function.


2005 ◽  
Vol 16 (7) ◽  
pp. 3107-3116 ◽  
Author(s):  
Anindya Ghosh-Roy ◽  
Bela S. Desai ◽  
Krishanu Ray

Toward the end of spermiogenesis, spermatid nuclei are compacted and the clonally related spermatids individualize to become mature and active sperm. Studies in Drosophila showed that caudal end-directed movement of a microfilament-rich structure, called investment cone, expels the cytoplasmic contents of individual spermatids. F-actin dynamics plays an important role in this process. Here we report that the dynein light chain 1 (DLC1) of Drosophila is involved in two separate cellular processes during sperm individualization. It is enriched around spermatid nuclei during postelongation stages and plays an important role in the dynein-dynactin–dependent rostral retention of the nuclei during this period. In addition, DDLC1 colocalizes with dynamin along investment cones and regulates F-actin assembly at this organelle by retaining dynamin along the cones. Interestingly, we found that this process does not require the other subunits of cytoplasmic dynein-dynactin complex. Altogether, these observations suggest that DLC1 could independently regulate multiple cellular functions and established a novel role of this protein in F-actin assembly in Drosophila.


1996 ◽  
Vol 16 (5) ◽  
pp. 1966-1977 ◽  
Author(s):  
T Dick ◽  
K Ray ◽  
H K Salz ◽  
W Chia

We report the molecular and genetic characterization of the cytoplasmic dynein light-chain gene, ddlc1, from Drosophila melanogaster. ddlc1 encodes the first cytoplasmic dynein light chain identified, and its genetic analysis represents the first in vivo characterization of cytoplasmic dynein function in higher eucaryotes. The ddlc1 gene maps to 4E1-2 and encodes an 89-amino-acid polypeptide with a high similarity to the axonemal 8-kDa outer-arm dynein light chain from Chlamydomonas flagella. Developmental Northern (RNA) blot analysis and ovary and embryo RNA in situ hybridizations indicate that the ddlc1 gene is expressed ubiquitously. Anti-DDLC1 antibody analyses show that the DDLC1 protein is localized in the cytoplasm. P-element-induced partial-loss-of-function mutations cause pleiotropic morphogenetic defects in bristle and wing development, as well as in oogenesis, and hence result in female sterility. The morphological abnormalities found in the ovaries are always associated with a loss of cellular shape and structure, as visualized by a disorganization of the actin cytoskeleton. Total-loss-of-function mutations cause lethality. A large proportion of mutant animals degenerate during embryogenesis, and the dying cells show morphological changes characteristic of apoptosis, namely, cell and nuclear condensation and fragmentation, as well as DNA degradation. Cloning of the human homolog of the ddlc1 gene, hdlc1, demonstrates that the dynein light-chain 1 is highly conserved in flies and humans. Northern blot analysis and epitope tagging show that the hdlc1 gene is ubiquitously expressed and that the human dynein light chain 1 is localized in the cytoplasm. hdlc1 maps to 14q24.


Development ◽  
1996 ◽  
Vol 122 (10) ◽  
pp. 2955-2963 ◽  
Author(s):  
R. Phillis ◽  
D. Statton ◽  
P. Caruccio ◽  
R.K. Murphey

Mutations in an 8 kDa (8x10(3) Mr) cytoplasmic dynein light chain disrupt sensory axon trajectories in the imaginal nervous system of Drosophila. Weak alleles are behaviorally mutant, female-sterile and exhibit bristle thinning and bristle loss. Null alleles are lethal in late pupal stages and alter neuronal anatomy within the imaginal CNS. We utilized P[Gal4] inserts to examine the axon projections of stretch receptor neurons and an engrailed-lacZ construct to characterize the anatomy of tactile neurons. In mutant animals both types of sensory neurons exhibited altered axon trajectories within the CNS, suggesting a defect in axon pathfinding. However, the alterations in axon trajectory did not prevent these axons from reaching their normal termination regions. In the alleles producing these neuronal phenotypes, expression of the cytoplasmic dynein 8 kDa light chain gene is completely absent. These results demonstrate a new function for the cytoplasmic dynein light chain in the regulation of axonogenesis and may provide a point of entry for studies of the role of cellular motors in growth cone guidance.


2004 ◽  
Vol 15 (7) ◽  
pp. 3005-3014 ◽  
Author(s):  
Min-gang Li ◽  
Madeline Serr ◽  
Eric A. Newman ◽  
Thomas S. Hays

Variations in subunit composition and modification have been proposed to regulate the multiple functions of cytoplasmic dynein. Here, we examine the role of the Drosophila ortholog of tctex-1, the 14-kDa dynein light chain. We show that the 14-kDa light chain is a bona fide component of Drosophila cytoplasmic dynein and use P element excision to generate flies that completely lack this dynein subunit. Remarkably, the null mutant is viable and the only observed defect is complete male sterility. During spermatid differentiation, the 14-kDa light chain is required for the localization of a nuclear “cap” of cytoplasmic dynein and for proper attachment between the sperm nucleus and flagellar basal body. Our results provide evidence that the function of the 14-kDa light chain in Drosophila is distinct from other dynein subunits and is not required for any essential functions in early development or in the adult organism.


2000 ◽  
Vol 74 (21) ◽  
pp. 10212-10216 ◽  
Author(s):  
Hélène Raux ◽  
Anne Flamand ◽  
Danielle Blondel

ABSTRACT The rabies virus P protein is involved in viral transcription and replication but its precise function is not clear. We investigated the role of P (CVS strain) by searching for cellular partners by using a two-hybrid screening of a PC12 cDNA library. We isolated a cDNA encoding a 10-kDa dynein light chain (LC8). LC8 is a component of cytoplasmic dynein involved in the minus end-directed movement of organelles along microtubules. We confirmed that this molecule interacts with P by coimmunoprecipitation in infected cells and in cells transfected with a plasmid encoding P protein. LC8 was also detected in virus particles. Series of deletions from the N- and C-terminal ends of P protein were used to map the LC8-binding domain to the central part of P (residues 138 to 172). These results are relevant to speculate that dynein may be involved in the axonal transport of rabies virus along microtubules through neuron cells.


2017 ◽  
Vol 91 (10) ◽  
Author(s):  
Tatiana Opazo ◽  
Andrea Garcés ◽  
Diego Tapia ◽  
Felipe Barraza ◽  
Angélica Bravo ◽  
...  

ABSTRACT How murine leukemia virus (MLV) travels from the cell membrane to the nucleus and the mechanism for nuclear entry of MLV DNA in dividing cells still remain unclear. It seems likely that the MLV preintegration complex (PIC) interacts with cellular proteins to perform these tasks. We recently published that the microtubule motor cytoplasmic dynein complex and its regulator proteins interact with the MLV PIC at early times of infection, suggesting a functional interaction between the incoming viral particles, the dynein complex, and dynein regulators. To better understand the role of the dynein complex in MLV infection, we performed short hairpin RNA (shRNA) screening of the dynein light chains on MLV infection. We found that silencing of a specific light chain of the cytoplasmic dynein complex, DYNLRB2, reduced the efficiency of infection by MLV reporter viruses without affecting HIV-1 infection. Furthermore, the overexpression of DYNLRB2 increased infection by MLV. We conclude that the DYNLRB2 light chain of the cytoplasmic dynein complex is an important and specific piece of the host machinery needed for MLV infection. IMPORTANCE Retroviruses must reach the chromatin of their host to integrate their viral DNA, but first they must get into the nucleus. The cytoplasm is a crowded environment in which simple diffusion is slow, and thus viruses utilize retrograde transport along the microtubule network, mediated by the dynein complex. Different viruses use different components of this multisubunit complex. We have found that murine leukemia virus (MLV) associates functionally and specifically with the dynein light chain DYNLRB2, which is required for infection. Our study provides more insight into the molecular requirements for retrograde transport of the MLV preintegration complex and demonstrates, for the first time, a role for DYNLRB2 in viral infection.


2009 ◽  
Vol 83 (13) ◽  
pp. 6952-6956 ◽  
Author(s):  
Toru Kubota ◽  
Mayumi Matsuoka ◽  
Tsung-Hsien Chang ◽  
Mike Bray ◽  
Steven Jones ◽  
...  

ABSTRACT The viral protein VP35 of ebolavirus (EBOV) is implicated to have diverse roles in the viral life cycle. We employed a yeast two-hybrid screen to search for VP35 binding partners and identified the cytoplasmic dynein light chain (DLC8) as a protein that interacts with VP35. Mapping analysis unraveled a consensus motif, SQTQT, within VP35 through which VP35 binds to DLC8. The disruption of DLC8 binding does not affect the ability of VP35 to inhibit type I IFN production. Given that VP35 from various EBOV species interacts with DLC8, this interaction may have a role in regulating the EBOV life cycle.


eLife ◽  
2013 ◽  
Vol 2 ◽  
Author(s):  
Sheng Min Shih ◽  
Benjamin D Engel ◽  
Fatih Kocabas ◽  
Thomas Bilyard ◽  
Arne Gennerich ◽  
...  

The assembly and maintenance of all cilia and flagella require intraflagellar transport (IFT) along the axoneme. IFT has been implicated in sensory and motile ciliary functions, but the mechanisms of this relationship remain unclear. Here, we used Chlamydomonas flagellar surface motility (FSM) as a model to test whether IFT provides force for gliding of cells across solid surfaces. We show that IFT trains are coupled to flagellar membrane glycoproteins (FMGs) in a Ca2+-dependent manner. IFT trains transiently pause through surface adhesion of their FMG cargos, and dynein-1b motors pull the cell towards the distal tip of the axoneme. Each train is transported by at least four motors, with only one type of motor active at a time. Our results demonstrate the mechanism of Chlamydomonas gliding motility and suggest that IFT plays a major role in adhesion-induced ciliary signaling pathways.


Sign in / Sign up

Export Citation Format

Share Document