scholarly journals Functional interaction between dynein light chain and intermediate chain is required for mitotic spindle positioning

2011 ◽  
Vol 22 (15) ◽  
pp. 2690-2701 ◽  
Author(s):  
Melissa D. Stuchell-Brereton ◽  
Amanda Siglin ◽  
Jun Li ◽  
Jeffrey K. Moore ◽  
Shubbir Ahmed ◽  
...  
Keyword(s):  
Light Chain ◽  
Direct Evidence ◽  
Retrograde Transport ◽  
Cytoplasmic Dynein ◽  
Dynein Light Chain ◽  
Spindle Positioning ◽  
Dynein Motor ◽  
Intermediate Chains ◽  
Activator Complex

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.

scholarly journals Dynein Light Chain 1 Regulates Dynamin-mediated F-Actin Assembly during Sperm Individualization in Drosophila

2005 ◽  
Vol 16 (7) ◽  
pp. 3107-3116 ◽  
Author(s):  
Anindya Ghosh-Roy ◽  
Bela S. Desai ◽  
Krishanu Ray
Keyword(s):  
Light Chain ◽  
Cytoplasmic Dynein ◽  
Actin Dynamics ◽  
Dynein Light Chain ◽  
Actin Assembly ◽  
Cellular Functions ◽  
Directed Movement ◽  
Cellular Processes ◽  
Dynactin Complex

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.

scholarly journals The Drosophila tctex-1 Light Chain Is Dispensable for Essential Cytoplasmic Dynein Functions but Is Required during Spermatid Differentiation

2004 ◽  
Vol 15 (7) ◽  
pp. 3005-3014 ◽  
Author(s):  
Min-gang Li ◽  
Madeline Serr ◽  
Eric A. Newman ◽  
Thomas S. Hays
Keyword(s):  
Light Chain ◽  
Cytoplasmic Dynein ◽  
Sperm Nucleus ◽  
P Element ◽  
Dynein Light Chain ◽  
Null Mutant ◽  
Multiple Functions ◽  
Bona Fide ◽  
Adult Organism

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.

scholarly journals Interaction of the Rabies Virus P Protein with the LC8 Dynein Light Chain

2000 ◽  
Vol 74 (21) ◽  
pp. 10212-10216 ◽  
Author(s):  
Hélène Raux ◽  
Anne Flamand ◽  
Danielle Blondel
Keyword(s):  
Rabies Virus ◽  
Light Chain ◽  
Cytoplasmic Dynein ◽  
Dynein Light Chain ◽  
Directed Movement ◽  
Virus Particles ◽  
P Protein ◽  
Infected Cells ◽  
Transcription And Replication

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.

scholarly journals Functional Evidence of the Involvement of the Dynein Light Chain DYNLRB2 in Murine Leukemia Virus Infection

2017 ◽  
Vol 91 (10) ◽  
Author(s):  
Tatiana Opazo ◽  
Andrea Garcés ◽  
Diego Tapia ◽  
Felipe Barraza ◽  
Angélica Bravo ◽  
...  
Keyword(s):  
Light Chain ◽  
Murine Leukemia Virus ◽  
Leukemia Virus ◽  
Retrograde Transport ◽  
Cytoplasmic Dynein ◽  
Dynein Light Chain ◽  
Preintegration Complex ◽  
Microtubule Network ◽  
Simple Diffusion ◽  
Murine Leukemia

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.

scholarly journals Dynein light chain 1 and a spindle-associated adaptor promote dynein asymmetry and spindle orientation

2012 ◽  
Vol 198 (6) ◽  
pp. 1039-1054 ◽  
Author(s):  
Anja K. Dunsch ◽  
Dean Hammond ◽  
Jennifer Lloyd ◽  
Lothar Schermelleh ◽  
Ulrike Gruneberg ◽  
...  
Keyword(s):  
Light Chain ◽  
Mitotic Spindle ◽  
Regulatory System ◽  
Cytoplasmic Dynein ◽  
Spindle Orientation ◽  
Growth Surface ◽  
Cell Cortex ◽  
Dynein Light Chain ◽  
Dynein Motor ◽  
Pulling Forces

The cytoplasmic dynein motor generates pulling forces to center and orient the mitotic spindle within the cell. During this positioning process, dynein oscillates from one pole of the cell cortex to the other but only accumulates at the pole farthest from the spindle. Here, we show that dynein light chain 1 (DYNLL1) is required for this asymmetric cortical localization of dynein and has a specific function defining spindle orientation. DYNLL1 interacted with a spindle-microtubule–associated adaptor formed by CHICA and HMMR via TQT motifs in CHICA. In cells depleted of CHICA or HMMR, the mitotic spindle failed to orient correctly in relation to the growth surface. Furthermore, CHICA TQT motif mutants localized to the mitotic spindle but failed to recruit DYNLL1 to spindle microtubules and did not correct the spindle orientation or dynein localization defects. These findings support a model where DYNLL1 and CHICA-HMMR form part of the regulatory system feeding back spindle position to dynein at the cell cortex.

scholarly journals Egalitarian binding partners, Dynein Light Chain and Bicaudal-D, act sequentially to link mRNA to the Dynein motor

2019 ◽  
Author(s):  
Chandler H. Goldman ◽  
Rajalakshmi Veeranan-Karmegam ◽  
Hannah Neiswender ◽  
Graydon B. Gonsalvez
Keyword(s):  
Light Chain ◽  
Rna Binding ◽  
Rna Binding Protein ◽  
Mrna Localization ◽  
Null Alleles ◽  
Dynein Light Chain ◽  
Binding Partners ◽  
Dynein Motor ◽  
Microtubule Motors

AbstractA widely conserved mechanism of polarity establishment is the localization of mRNA to specific cellular regions. While it is clear that many mRNAs are transported to their destinations along microtubule tracks, much less is known regarding the mechanism by which these mRNAs are linked to microtubule motors. The RNA binding protein Egalitarian (Egl) is necessary for localization of several mRNAs in Drosophila oocytes and embryos. In addition to binding RNA, Egl also interacts with Dynein light chain (Dlc) and Bicaudal-D (BicD). The role of Dlc and BicD in mRNA localization has remained elusive. Like Egl, both proteins are required for oocyte specification. Null alleles in these genes result in an oogenesis block. In this report, we used an innovative approach to overcome the oogenesis block. Our findings reveal that the primary function of Dlc is to promote Egl dimerization. Loss of dimerization compromises the ability of Egl to bind RNA. Consequently, Egl is not bound to cargo, and is not able to efficiently associate with BicD and the Dynein motor. Our results therefore identify the key molecular steps required for assembling a localization competent mRNP.

scholarly journals Crystal Structure of Dynein Light Chain TcTex-1

2005 ◽  
Vol 280 (23) ◽  
pp. 21981-21986 ◽  
Author(s):  
John C. Williams ◽  
Hui Xie ◽  
Wayne A. Hendrickson
Keyword(s):  
Crystal Structure ◽  
Light Chain ◽  
Structural Alignment ◽  
Cytoplasmic Dynein ◽  
Dynein Light Chain ◽  
Nitricoxide Synthase ◽  
Dynein Motor ◽  
Poliovirus Receptor ◽  
Dynein Intermediate Chain ◽  
Oxide Synthase

TcTex-1, one of three dynein light chains of the dynein motor complex, has been implicated in targeting and binding cargoes to cytoplasmic dynein for retrograde or apical transport. Interactions between TcTex-1 and a diverse set of proteins such as the dynein intermediate chain, Fyn, DOC2, FIP1, the poliovirus receptor, CD155, and the rhodopsin cytoplasmic tail have been reported; yet, despite the broad range of targets, a consensus binding sequence remains uncertain. Consequently, we have solved the crystal structure of the full-length Drosophila homolog of TcTex-1 to 1.7 Å resolution using MAD phasing to gain insight into its function and target specificity. The structure is homodimeric with a domain swapping of β-strand 2 and has a fold similar to the dynein light chain, LC8. Based on structural alignment, the TcTex-1 and LC8 sequences show no identity, although the root mean square deviation between secondary structural elements is less than 1.6 Å. Moreover, the N terminus, which is equivalent to β-strand 1 in LC8, is splayed out and binds to a crystallographic dimer as an anti-parallel β-strand at the same position as the neuronal nitric-oxide synthase peptide in the LC8 complex. Similarity to LC8 and comparison to the LC8-neuronal nitricoxide synthase complex suggest that TcTex-1 binds its targets in a similar manner as LC8 and provides insight to the lack of strict sequence identity among the targets for TcTex-1.

scholarly journals Dynein light chain Dynlrb2 is essential for Murine leukemia virus traffic and nuclear entry.

2021 ◽  
Author(s):  
Gianfranco Pietrantoni ◽  
Aracelly Gaete-Argel ◽  
Diego Herrera-Rojo ◽  
Rodrigo Ibarra-Karmy ◽  
Fernando J Bustos ◽  
...  
Keyword(s):  
Light Chain ◽  
Murine Leukemia Virus ◽  
Essential Role ◽  
Leukemia Virus ◽  
Retrograde Transport ◽  
Cytoplasmic Dynein ◽  
Dynein Light Chain ◽  
Nuclear Entry ◽  
Preintegration Complex ◽  
Murine Leukemia

Murine leukemia virus (MLV) requires the infected cell to divide to access the nucleus to integrate into the host genome. It has been determined that MLV uses the microtubule and actin network to reach the nucleus at the early stages of infection. Several studies have shown that viruses use the dynein motor protein associated with microtubules for their displacement. We have previously reported that Dynein light chain roadblock-type2 (Dynlrb2) knock-down significantly decreases MLV infection compared to non-silenced cells, suggesting a functional association between this dynein light chain and MLV preintegration complex (PIC). Here we aim to determine if the dynein complex Dynlrb2 subunit plays an essential role in the retrograde transport of MLV. For this, an MLV mutant containing the green fluorescent protein (GFP) fused to the viral protein p12 was used to assay the PIC localization and speed in cells were the expression of Dynlrb2 was modulated. We found a significant decrease in the arrival of MLV PIC to the nucleus and a reduced net speed of MLV PICs when Dynlrb2 was knocked down. On the contrary, an increase in nuclear localization is observed when Dynlrb2 is overexpressed. Our results suggest that Dynlrb2 plays an essential role in MLV retrograde transport. Importance Different viruses use different components of cytoplasmic dynein complex to traffic to their replication site. We have found that murine leukemia virus (MLV) depends on dynein light chain Dynlrb2 for infection, retrograde traffic and nuclear entry. Our study provides new information regarding the molecular requirements for retrograde transport of MLV preintegration complex and demonstrates the essential role of Dynlrb2 in MLV infection.

scholarly journals Identification and developmental regulation of a neuron-specific subunit of cytoplasmic dynein.

1996 ◽  
Vol 7 (2) ◽  
pp. 331-343 ◽  
Author(s):  
K K Pfister ◽  
M W Salata ◽  
J F Dillman ◽  
E Torre ◽  
R J Lye
Keyword(s):  
Axonal Transport ◽  
Developmental Regulation ◽  
Cytoplasmic Dynein ◽  
Retrograde Axonal Transport ◽  
Protein Isoforms ◽  
Cultured Neurons ◽  
Developmentally Regulated ◽  
Time Period ◽  
Intermediate Chains

Cytoplasmic dynein is the microtubule minus-end-directed motor for the retrograde axonal transport of membranous organelles. Because of its similarity to the intermediate chains of flagellar dynein, the 74-kDa intermediate chain (IC74) subunit of dynein is thought to be involved in binding dynein to its membranous organelle cargo. Previously, we identified six isoforms of the IC74 cytoplasmic dynein subunit in the brain. We further demonstrated that cultured glia and neurons expressed different dynein IC74 isoforms and phospho-isoforms. Two isoforms were observed when dynein from glia was analyzed. When dynein from cultured neurons was analyzed, six IC74 isoforms were observed, although the relative amounts of the dynein isoforms from cultured neurons differed from those found in dynein from brain. To better understand the role of the neuronal IC74 isoforms and identify neuron-specific IC74 dynein subunits, the expression of the IC74 protein isoforms and mRNAs of various tissues were compared. As a result of this comparison, the identity of each of the isoform spots observed on two-dimensional gels was correlated with the products of each of the IC74 mRNAs. We also found that between the fifteenth day of gestation (E15) and the fifth day after birth (P5), the relative expression of the IC74 protein isoforms changes, demonstrating that the expression of IC74 isoforms is developmentally regulated in brain. During this time period, there is relatively little change in the abundance of the various IC74 mRNAs. The E15 to P5 time period is one of rapid process extension and initial pattern formation in the rat brain. This result indicates that the changes in neuronal IC74 isoforms coincide with neuronal differentiation, in particular the extension of processes. This suggests a role for the neuronal IC74 isoforms in the establishment or regulation of retrograde axonal transport.

scholarly journals Cytoplasmic dynein (ddlc1) mutations cause morphogenetic defects and apoptotic cell death in Drosophila melanogaster.

1996 ◽  
Vol 16 (5) ◽  
pp. 1966-1977 ◽  
Author(s):  
T Dick ◽  
K Ray ◽  
H K Salz ◽  
W Chia
Keyword(s):  
Drosophila Melanogaster ◽  
Light Chain ◽  
Blot Analysis ◽  
Cytoplasmic Dynein ◽  
P Element ◽  
Female Sterility ◽  
Dynein Light Chain ◽  
Loss Of Function ◽  
Light Chain Gene

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.

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