scholarly journals CLIPR-59, a new trans-Golgi/TGN cytoplasmic linker protein belonging to the CLIP-170 family

2002 ◽  
Vol 156 (4) ◽  
pp. 631-642 ◽  
Author(s):  
Franck Perez ◽  
Karin Pernet-Gallay ◽  
Clément Nizak ◽  
Holly V. Goodson ◽  
Thomas E. Kreis ◽  
...  
Keyword(s):  
Molecular Motors ◽  
Membrane Targeting ◽  
Related Protein ◽  
Recycling Endosome ◽  
Microtubule Network ◽  
Carboxy Terminal Domain ◽  
Cell Organization ◽  
Carboxy Terminal ◽  
Necessary And Sufficient

The microtubule cytoskeleton plays a fundamental role in cell organization and membrane traffic in higher eukaryotes. It is well established that molecular motors are involved in membrane–microtubule interactions, but it has also been proposed that nonmotor microtubule-binding (MTB) proteins known as CLIPs (cytoplasmic linker proteins) have basic roles in these processes. We report here the characterization of CLIPR-59, a CLIP-170–related protein localized to the trans-most part of the Golgi apparatus. CLIPR-59 contains an acidic region followed by three ankyrin-like repeats and two CLIP-170–related MTB motifs. We show that the 60–amino acid–long carboxy-terminal domain of CLIPR-59 is necessary and sufficient to achieve Golgi targeting, which represents the first identification of a membrane targeting domain in a CLIP-170–related protein. The MTB domain of CLIPR-59 is functional because it localizes to microtubules when expressed as a fragment in HeLa cells. However, our results suggest that this domain is normally inhibited by the presence of adjacent domains, because neither full-length CLIPR-59 nor a CLIPR-59 mutant missing its membrane-targeting region localize to microtubules. Consistent with this observation, overexpression of CLIPR-59 does not affect the microtubule network. However, CLIPR-59 overexpression strongly perturbs early/recycling endosome–TGN dynamics, implicating CLIPR-59 in the regulation of this pathway.

scholarly journals Identification and characterization of a cDNA encoding mouse CAP: a homolog of the yeast adenylyl cyclase associated protein

1993 ◽  
Vol 105 (3) ◽  
pp. 777-785 ◽  
Author(s):  
A.B. Vojtek ◽  
J.A. Cooper
Keyword(s):  
Adenylyl Cyclase ◽  
Leading Edge ◽  
Northern Analysis ◽  
Reading Frame ◽  
Terminal Domain ◽  
Carboxy Terminal Domain ◽  
Acid Protein ◽  
Carboxy Terminal ◽  
Amino Acid Protein

CAP, an adenylyl cyclase associated protein, is present in Saccharomyces cerevisiae and Schizosaccharomyces pombe. In both organisms, CAP is bifunctional: the N-terminal domain binds to adenylyl cyclase, thereby enabling adenylyl cyclase to respond appropriately to upstream regulatory signals, such as RAS in S. cerevisiae; the C-terminal domain is required for cellular morphogenesis. Here, we describe the isolation of a cDNA encoding a CAP homolog from a higher eukaryote. The mouse CAP cDNA contains an open reading frame capable of encoding a 474 amino acid protein. The protein encoded by the mouse CAP cDNA shows extensive homology to the yeast CAP proteins, particularly in the central poly-proline rich region and in the C-terminal domain. By northern analysis, the CAP message appears to be ubiquitous, but not uniform. By indirect immunofluorescence, ectopically expressed mouse CAP protein is found in the cytoplasm of fibroblasts and, in migrating cells, at the leading edge. Expression of the mouse CAP cDNA in S. cerevisiae complements defects associated with loss of the yeast CAP carboxy-terminal domain. Hence, the function of the CAP carboxy-terminal domain has been conserved from yeast to mouse.

Functional and structural characterization of the kinase insert and the carboxy terminal domain in VEGF receptor 2 activation

2014 ◽  
Vol 28 (11) ◽  
pp. 4914-4923 ◽  
Author(s):  
Sandro Manni ◽  
Kaisa Kisko ◽  
Thomas Schleier ◽  
Jack Missimer ◽  
Kurt Ballmer‐Hofer
Keyword(s):  
Structural Characterization ◽  
Vegf Receptor ◽  
Terminal Domain ◽  
Carboxy Terminal Domain ◽  
Carboxy Terminal

scholarly journals Kinesin-related Smy1 enhances the Rab-dependent association of myosin-V with secretory cargo

2016 ◽  
Vol 27 (15) ◽  
pp. 2450-2462 ◽  
Author(s):  
Kyaw Myo Lwin ◽  
Donghao Li ◽  
Anthony Bretscher
Keyword(s):  
Molecular Motors ◽  
Essential Role ◽  
Secretory Vesicle ◽  
Rab Proteins ◽  
Secretory Vesicles ◽  
Molecular Function ◽  
Related Protein ◽  
Myosin V ◽  
Dimerization Domain ◽  
Cell Organization

The mechanisms by which molecular motors associate with specific cargo is a central problem in cell organization. The kinesin-like protein Smy1 of budding yeast was originally identified by the ability of elevated levels to suppress a conditional myosin-V mutation (myo2-66), but its function with Myo2 remained mysterious. Subsequently, Myo2 was found to provide an essential role in delivery of secretory vesicles for polarized growth and in the transport of mitochondria for segregation. By isolating and characterizing myo2 smy1 conditional mutants, we uncover the molecular function of Smy1 as a factor that enhances the association of Myo2 with its receptor, the Rab Sec4, on secretory vesicles. The tail of Smy1—which binds Myo2—its central dimerization domain, and its kinesin-like head domain are all necessary for this function. Consistent with this model, overexpression of full-length Smy1 enhances the number of Sec4 receptors and Myo2 motors per transporting secretory vesicle. Rab proteins Sec4 and Ypt11, receptors for essential transport of secretory vesicles and mitochondria, respectively, bind the same region on Myo2, yet Smy1 functions selectively in the transport of secretory vesicles. Thus a kinesin-related protein can function intimately with a myosin-V and its receptor in the transport of a specific cargo.

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