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Interaction of SPIN90 with syndapin is implicated in clathrin‐mediated endocytic pathway in fibroblasts
Author(s) -
Kim Sung Hyun,
Choi Hyun Jin,
Lee Kyoung Woo,
Hong Nan Hyung,
Sung Bong Hwan,
Choi Kyu Yeong,
Kim SeonMyung,
Chang Sunghoe,
Eom Soo Hyun,
Song Woo Keun
Publication year - 2006
Publication title -
genes to cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.912
H-Index - 115
eISSN - 1365-2443
pISSN - 1356-9597
DOI - 10.1111/j.1365-2443.2006.01008.x
Subject(s) - endocytic cycle , endocytosis , microbiology and biotechnology , biology , endosome , clathrin , internalization , dynamin , transferrin receptor , signal transducing adaptor protein , receptor mediated endocytosis , transferrin , phosphorylation , receptor , biochemistry , intracellular
SPIN90, a 90‐kDa Nck‐interacting protein with a SH3 domain, plays a role in sarcomere formation and myofibril assembly, and its phosphorylation is modulated by cell adhesion and Erk activation. Here we demonstrate that SPIN90 participates in receptor‐mediated endocytic pathway in fibroblasts. We identified syndapin (synaptic dynamin‐binding protein) as a SPIN90 interacting protein using yeast two‐hybrid screening. SPIN90 directly binds the SH3 domain of syndapin via its proline rich domain in vitro and in vivo and also associates with clathrin. Over‐expression of SPIN90‐full length in COS‐7 cells inhibited transferrin uptake, a marker of endocytosis. Interestingly, SPIN90‐PRD, a syndapin‐binding domain, significantly inhibited endocytosis, and the inhibition was reversed by co‐expression of syndapin. Depleting SPIN90 through antibody microinjection or Knocking it down using siRNAs also significantly inhibited transferrin internalization. Moreover, early endosomal marker proteins (EEA1 and Rab5) appeared to closely associate or partially co‐localize with SPIN90 in endosomes and an internalized FITC‐dextran and Texas Red‐EGF were found on the endosomes in association with SPIN90. Time‐lapse video showed that GFP‐SPIN90 travels with moving vesicles within living cells. Taken together, these findings suggest that SPIN90 is implicated in receptor‐mediated endocytic pathway in fibroblasts.