The Small GTPase Rab4A Interacts with the Central Region of Cytoplasmic Dynein Light Intermediate Chain-1

Autor: K A Fitzgerald, Alan G. Hendrick, Anna Bielli, Mary W. McCaffrey, Per-Ove Thörnqvist, Robert Finn
Rok vydání: 2001
Předmět:
Zdroj: Biochemical and Biophysical Research Communications. 281:1141-1153
ISSN: 0006-291X
DOI: 10.1006/bbrc.2001.4468
Popis: Rab4 belongs to the Rab family of small GTPases involved in the regulation of intracellular transport, and has been localized to early endosomes. We have employed the yeast two-hybrid system to identify proteins that specifically interact with Rab4AQ67L, a GTPase-deficient mutant form of Rab4A. Screening a mouse embryo cDNA library identified a clone (M449) that interacted with Rab4A in a nucleotide-dependent fashion. Data base searches identified this clone as the mouse cytoplasmic dynein light intermediate chain-1 (LIC-1). Based on this finding, the full-length equivalent human cytoplasmic dynein LIC-1 was isolated by PCR. When Rab4A was overexpressed together with either M449 or dynein LIC-1 in HeLa cells, the proteins were found to colocalize in the perinuclear region. We characterize the localization of both overexpressed human dynein LIC-1 and the endogenous protein with respect to microtubules and show that it concentrates to the microtubule-organizing center and mitotic spindle. Additionally, GFPRab4A endosomes localize to microtubules and are redistributed by nocodazole treatment. This is the first described interaction between cytoplasmic dynein, a retrograde motor protein, and a Rab protein.
Databáze: OpenAIRE