REI-1 Is a Guanine Nucleotide Exchange Factor Regulating RAB-11 Localization and Function in C. elegans Embryos.
The small GTPase Rab11 dynamically changes its location to regulate various cellular processes such as endocytic recycling, secretion, and cytokinesis. However, our knowledge of its upstream regulators is still limited. Here, we identify the RAB-11-interacting protein-1 (REI-1) as a unique family of guanine nucleotide exchange factors (GEFs) for RAB-11 in Caenorhabditis elegans. Although REI-1 and its human homolog SH3-binding protein 5 do not contain any known Rab-GEF domains, they exhibited strong GEF activity toward Rab11 in vitro. In C. elegans, REI-1 is expressed in the germline and co-localizes with RAB-11 on the late-Golgi membranes. The loss of REI-1 specifically impaired the targeting of RAB-11 to the late-Golgi compartment and the recycling endosomes in embryos and further reduced the RAB-11 distribution to the cleavage furrow, which resulted in cytokinesis delay. These results suggest that REI-1 is a GEF specifically regulating the RAB-11 localization and functions in early embryos.
Laboratory of Molecular Traffic, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Gunma 371-8512, Japan.
Aisa
A
Sakaguchi
Laboratory of Molecular Membrane Biology, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Gunma 371-8512, Japan.
Miyuki
M
Sato
Laboratory of Molecular Membrane Biology, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Gunma 371-8512, Japan.
Katsuya
K
Sato
Brain Science Institute, Saitama University, Saitama, Saitama 338-8570, Japan.
Keiko
K
Gengyo-Ando
Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan.
Tomohiro
T
Yorimitsu
Brain Science Institute, Saitama University, Saitama, Saitama 338-8570, Japan.
Junichi
J
Nakai
Laboratory of Molecular Traffic, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Gunma 371-8512, Japan.
Taichi
T
Hara
Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan.
Ken
K
Sato
Laboratory of Molecular Traffic, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Gunma 371-8512, Japan. Electronic address: sato-ken@gunma-u.ac.jp.
Ken
K
Sato
D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology / Q000235:genetics*; D029742:Caenorhabditis elegans Proteins / Q000096:biosynthesis / Q000235:genetics*; D048749:Cytokinesis / Q000235:genetics*; D004625:Embryo, Nonmammalian; D047108:Embryonic Development / Q000235:genetics*; D011992:Endosomes / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics*; D006801:Humans; D034622:RNA Interference; D033921:Vesicular Transport Proteins / Q000096:biosynthesis / Q000235:genetics*
D029742:Caenorhabditis elegans Proteins; D020662:Guanine Nucleotide Exchange Factors; C000604780:REI-1 protein, C elegans; D033921:Vesicular Transport Proteins; C558453:rab-11.1 protein, C elegans