HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 282, Issue 36, 26481-26489, September 7, 2007

This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 282/36/26481    most recent M703815200v1 Submit a Letter to Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Uezu, A. Articles by Nakanishi, H. Search for Related Content PubMed PubMed Citation Articles by Uezu, A. Articles by Nakanishi, H. Social Bookmarking                      What's this?

SGIP1 Is an Endocytic Protein That Directly Interacts with Phospholipids and Eps15^*

Akiyoshi Uezu, Ayaka Horiuchi, Kousuke Kanda, Naoya Kikuchi, Kazuaki Umeda, Kazuya Tsujita¹, Shiro Suetsugu², Norie Araki^¶, Hideyuki Yamamoto³, Tadaomi Takenawa¹, and Hiroyuki Nakanishi⁴

From the Department of Molecular Pharmacology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556, the Department of Biochemistry, Institute of Medical Science, University of Tokyo, Shirokanedai, Minato-ku, Tokyo 108-8639, and the ^¶Department of Tumor Genetics and Biology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjyo, Kumamoto 860-8556, Japan

SGIP1 has been shown to be an endophilin-interacting protein that regulates energy balance, but its function is not fully understood. Here, we identified its splicing variant of SGIP1 and named it SGIP1. SGIP1 bound to phosphatidylserine and phosphoinositides and deformed the plasma membrane and liposomes into narrow tubules, suggesting the involvement in vesicle formation during endocytosis. SGIP1 furthermore bound to Eps15, an important adaptor protein of clathrin-mediated endocytic machinery. SGIP1 was colocalized with Eps15 and the AP-2 complex. Upon epidermal growth factor (EGF) stimulation, SGIP1 was colocalized with EGF at the plasma membrane, indicating the localization of SGIP1 at clathrin-coated pits/vesicles. SGIP1 overexpression reduced transferrin and EGF endocytosis. SGIP1 knockdown reduced transferrin endocytosis but not EGF endocytosis; this difference may be due to the presence of redundant pathways in EGF endocytosis. These results suggest that SGIP1 plays an essential role in clathrin-mediated endocytosis by interacting with phospholipids and Eps15.

Received for publication, May 9, 2007 , and in revised form, July 6, 2007.

The nucleotide sequence(s) reported in this paper has been submitted to GenBank^TM/EBI Data Bank with the accession number(s) AB262963 and AB262964.

^* This study was supported by grants-in-aids for Cancer Research and for Scientific Research on Priority Areas from the Ministry of Education, Culture, Sports, Science, and Technology of Japan. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

The on-line version of this article (available at http://www.jbc.org) contains two supplemental figures.

¹ Present address: Dept. of Lipid Biochemistry, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan.

² Present address: Laboratory of Membrane and Cytoskeleton Dynamics, Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan.

³ Present address: Dept. of Biochemistry, Graduate School of Medicine, University of the Ryukyus, Okinawa 903-0215, Japan.

⁴ To whom correspondence should be addressed. Tel.: 81-96-373-5074; Fax: 81-96-373-5078; E-mail: hnakanis{at}gpo.kumamoto-u.ac.jp.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				G. E. Craft, M. E. Graham, N. Bache, M. R. Larsen, and P. J. Robinson The in Vivo Phosphorylation Sites in Multiple Isoforms of Amphiphysin I from Rat Brain Nerve Terminals Mol. Cell. Proteomics, June 1, 2008; 7(6): 1146 - 1161. [Abstract] [Full Text] [PDF]

				T. Sakamoto, A. Uezu, S. Kawauchi, T. Kuramoto, K. Makino, K. Umeda, N. Araki, H. Baba, and H. Nakanishi Mass spectrometric analysis of microtubule co-sedimented proteins from rat brain. Genes Cells, April 1, 2008; 13(4): 295 - 312. [Abstract] [Full Text] [PDF]