Coatomer-bound Cdc42 regulates dynein recruitment to COPI vesicles

Department of Physiology and Biophysics, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, IA 52242, USA.
The Journal of Cell Biology (Impact Factor: 9.69). 06/2005; 169(3):383-9. DOI: 10.1083/jcb.200501157
Source: PubMed

ABSTRACT Cytoskeletal dynamics at the Golgi apparatus are regulated in part through a binding interaction between the Golgi-vesicle coat protein, coatomer, and the regulatory GTP-binding protein Cdc42 (Wu, W.J., J.W. Erickson, R. Lin, and R.A. Cerione. 2000. Nature. 405:800-804; Fucini, R.V., J.L. Chen, C. Sharma, M.M. Kessels, and M. Stamnes. 2002. Mol. Biol. Cell. 13:621-631). The precise role of this complex has not been determined. We have analyzed the protein composition of Golgi-derived coat protomer I (COPI)-coated vesicles after activating or inhibiting signaling through coatomer-bound Cdc42. We show that Cdc42 has profound effects on the recruitment of dynein to COPI vesicles. Cdc42, when bound to coatomer, inhibits dynein binding to COPI vesicles whereas preventing the coatomer-Cdc42 interaction stimulates dynein binding. Dynein recruitment was found to involve actin dynamics and dynactin. Reclustering of nocodazole-dispersed Golgi stacks and microtubule/dynein-dependent ER-to-Golgi transport are both sensitive to disrupting Cdc42 mediated signaling. By contrast, dynein-independent transport to the Golgi complex is insensitive to mutant Cdc42. We propose a model for how proper temporal regulation of motor-based vesicle translocation could be coupled to the completion of vesicle formation.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Transcranial magnetic stimulation (TMS) is a non invasive technique of brain stimulation which could be an interesting therapeutic tool in addictive disorders, being offline repetitive TMS (rTMS) the main strategy used due to it allows to disrupt underlying brain areas and examine behavioral consequences, (Knoch et al., 2006).There are some evidences that rTMS over the dorso-lateral prefrontal (DLPF) cortex is effective reducing craving in several drugs, such as cocaine, tobacco and alcohol (Camprodon et al., 2007; Amiaz et al., 2009; Mishra et al. 2010). In fact, a decrease on cocaine craving could be observed with a single session of rTMS. Complementary, the application of single and paired-pulse TMS in controlled paradigms is a novel and promising strategy in this area: recent results showed that reward modulated TMS-induced motor-evoked potentials, showing greater cortical inhibition during reward expectation (Gupta and Aron, 2010).Regarding alcohol abuse, there is a narrow relation between alcohol consumption and impulsiveness. On one hand, alcohol consumption produces impulsive behavior and desinhibition (Marinkovic et al. 2011); and on the other hand, impulsiveness personality trait predisposes to abusive alcohol consumption (Magid et al. 2007).Considering these evidences and the effectiveness of rTMS as therapeutic tool, use rTMS to reduce impulsivity could be a new approach to alcohol disorders treatment. Prefrontal cortex is a good candidate for this purpose since its pivotal role in impulsiveness behavior (Crews and Boettinger, 2009). Thus, we suggest that high frequency rTMS stimulation could improve the ability of alcohol abusers for control their drinking impulse.
    European Psychiatry 01/2012; 27:1. DOI:10.1016/S0924-9338(12)74247-5 · 3.21 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This review summarizes the data describing the role of cellular microtubules in transportation of membrane vesicles - transport containers for secreted proteins or lipids. Most events of early vesicular transport in animal cells (from the endoplasmic reticulum to the Golgi apparatus and in the opposite recycling direction) are mediated by microtubules and microtubule motor proteins. Data on the role of dynein and kinesin in early vesicle transport remain controversial, probably because of the differentiated role of these proteins in the movements of vesicles or membrane tubules with various cargos and at different stages of secretion and retrograde transport. Microtubules and dynein motor protein are essential for maintaining a compact structure of the Golgi apparatus; moreover, there is a set of proteins that are essential for Golgi compactness. Dispersion of ribbon-like Golgi often occurs under physiological conditions in interphase cells. Golgi is localized in the leading part of crawling cultured fibroblasts, which also depends on microtubules and dynein. The Golgi apparatus creates its own system of microtubules by attracting γ-tubulin and some microtubule-associated proteins to membranes. Molecular mechanisms of binding microtubule-associated and motor proteins to membranes are very diverse, suggesting the possibility of regulation of Golgi interaction with microtubules during cell differentiation. To illustrate some statements, we present our own data showing that the cluster of vesicles induced by expression of constitutively active GTPase Sar1a[H79G] in cells is dispersed throughout the cell after microtubule disruption. Movement of vesicles in cells containing the intermediate compartment protein ERGIC53/LMANI was inhibited by inhibiting dynein. Inhibiting protein kinase LOSK/SLK prevented orientation of Golgi to the leading part of crawling cells, but the activity of dynein was not inhibited according to data on the movement of ERGIC53/LMANI-marked vesicles.
    Biochemistry (Moscow) 09/2014; 79(9):879-93. DOI:10.1134/S0006297914090053 · 1.35 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Influenza virus neuraminidase (NA) is a major viral envelope glycoprotein, which plays a critical role in viral infection. Although NA functional domains have been determined previously, the precise role of the amino acids located at the N-terminus of avian H5N1 NA for protein expression and intracellular transport to the host plasma membrane is not fully understood. In the present study, a series of N-terminal truncation or deletion mutants of H5N1 NA were generated and their expression and intracellular trafficking were investigated. Protein expression from mutants NA Delta 20, NA Delta 35, NA Delta 40, NA Delta 7-20 and NA Delta 7-35 was undetectable by immunoblotting and by performing NA activity assays. Mutants NA Delta 6, NA Delta 11 and NA Delta 15-20 showed a marked decreased in protein expression, whereas mutants NA Delta 7-15 and NA Delta 15 displayed a slight increase in protein expression, compared with that of the native NA protein. These data suggest that amino acid residues 16-20 are vital for NA protein expression, while amino acids 7-15 might suppress NA protein expression. In deletion mutants NA Delta 7-15 and NA Delta 15 there was an accumulation of NA protein at the juxta-nuclear region, with reduced expression of NA at the cell surface. Although active Cdc42 could promote transport of wild-type NA to the host cell surface, this member of the Rho family of GTPases failed to regulate transport of mutants NA Delta 7-15 and NA Delta 15. The results of the study reveal that amino acid residues 7-15 of H5N1 NA are critical for its biosynthetic transport to the host cell surface.
    The Veterinary Journal 10/2014; 202(3). DOI:10.1016/j.tvjl.2014.10.015 · 2.17 Impact Factor

Full-text (4 Sources)

Available from
Jun 10, 2014