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

J. Biol. Chem., Vol. 279, Issue 46, 47704-47710, November 12, 2004

This Article Full Text Full Text (PDF) All Versions of this Article: 279/46/47704    most recent M407016200v1 Alert me when this article is cited 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 Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Tanida, I. Articles by Kominami, E. Search for Related Content PubMed PubMed Citation Articles by Tanida, I. Articles by Kominami, E. Social Bookmarking                      What's this?

Human Light Chain 3/MAP1LC3B Is Cleaved at Its Carboxyl-terminal Met¹²¹ to Expose Gly¹²⁰ for Lipidation and Targeting to Autophagosomal Membranes^*

Isei Tanida, Takashi Ueno, and Eiki Kominami

From the Department of Biochemistry, Juntendo University School of Medicine, Tokyo 113-8421, Japan

Human light chain 3/MAP1LC3B, an autophagosomal ortholog of yeast Atg8, is conjugated to phospholipid (PL) via ubiquitylation-like reactions mediated by human Atg7 and Atg3. Since human Atg4B was found to cleave the carboxyl terminus of MAP1LC3B in vitro, we hypothesized that this exposes its carboxyl-terminal Gly¹²⁰. It was recently reported, however, that when Myc-MAP1LC3B-His is expressed in HEK293 cells, its carboxyl terminus is not cleaved. (Tanida, I., Sou, Y.-s., Ezaki, J., Minematsu-Ikeguchi, N., Ueno, T., and Kominami, E. (2004) J. Biol. Chem. 279, 36268–36276). To clarify this contradiction, we sought to determine whether the carboxyl terminus of MAP1LC3B is cleaved to expose Gly¹²⁰ for further ubiquitylation-like reactions. When MAP1LC3B-3xFLAG and Myc-MAP1LC3B-His were expressed in HEK293 cells, their carboxyl termini were cleaved, whereas there was little cleavage of mutant proteins MAP1LC3B^G120A-3xFLAG and Myc-MAP1LC3B^G120A-His, containing Ala in place of Gly¹²⁰. An in vitro assay showed that Gly¹²⁰ is essential for carboxyl-terminal cleavage by human Atg4B as well as for formation of the intermediates Atg7-MAP1LC3B (ubiquitin-activating enzyme-substrate) and Atg3-MAP1LC3B (ubiquitin carrier protein-substrate). Recombinant MAP1LC3B-PL was fractionated into the 100,000 x g pellet in a manner similar to that shown for endogenous MAP1LC3B-PL. RNA interference of MAP1LC3B mRNA resulted in a decrease in both endogenous MAP1LC3B-PL and MAP1LC3B. These results indicate that the carboxyl terminus of MAP1LC3B is cleaved to expose Gly¹²⁰ for further ubiquitylation-like reactions.

Received for publication, June 23, 2004 , and in revised form, August 19, 2004.

^* This work was supported in part by Grants-in-aid for Scientific Research 15590254 (to I. T.), 16370063 (to T. U.), and 1246101 (to E. K.) and Grant-in-aid 12146205 for Scientific Research on Priority Areas (to E. K.) from the Ministry of Education, Science, Sports, and Culture of Japan and by a grant from the Science Research Promotion Fund of the Japan Private School Promotion Foundation (to E. K.). 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.

To whom correspondence should be addressed: Dept. of Biochemistry, Juntendo University School of Medicine, 2-1-1, Hongo, Bunkyo-ku, Tokyo 113-8421, Japan. Tel.: 81-3-5802-1031; Fax: 81-3-5802-5889; E-mail: kominami{at}med.juntendo.ac.jp.

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

This article has been cited by other articles:

				M. P. Taylor and K. Kirkegaard Modification of Cellular Autophagy Protein LC3 by Poliovirus J. Virol., November 15, 2007; 81(22): 12543 - 12553. [Abstract] [Full Text] [PDF]

				S. Pankiv, T. H. Clausen, T. Lamark, A. Brech, J.-A. Bruun, H. Outzen, A. Overvatn, G. Bjorkoy, and T. Johansen p62/SQSTM1 Binds Directly to Atg8/LC3 to Facilitate Degradation of Ubiquitinated Protein Aggregates by Autophagy J. Biol. Chem., August 17, 2007; 282(33): 24131 - 24145. [Abstract] [Full Text] [PDF]

				C. D. Pacheco, R. Kunkel, and A. P. Lieberman Autophagy in Niemann-Pick C disease is dependent upon Beclin-1 and responsive to lipid trafficking defects Hum. Mol. Genet., June 15, 2007; 16(12): 1495 - 1503. [Abstract] [Full Text] [PDF]

				E. Fujita, Y. Kouroku, A. Isoai, H. Kumagai, A. Misutani, C. Matsuda, Y. K. Hayashi, and T. Momoi Two endoplasmic reticulum-associated degradation (ERAD) systems for the novel variant of the mutant dysferlin: ubiquitin/proteasome ERAD(I) and autophagy/lysosome ERAD(II) Hum. Mol. Genet., March 15, 2007; 16(6): 618 - 629. [Abstract] [Full Text] [PDF]

				U. Akar, B. Ozpolat, K. Mehta, J. Fok, Y. Kondo, and G. Lopez-Berestein Tissue Transglutaminase Inhibits Autophagy in Pancreatic Cancer Cells Mol. Cancer Res., March 1, 2007; 5(3): 241 - 249. [Abstract] [Full Text] [PDF]

				T. Kouno, M. Mizuguchi, I. Tanida, T. Ueno, T. Kanematsu, Y. Mori, H. Shinoda, M. Hirata, E. Kominami, and K. Kawano Solution Structure of Microtubule-associated Protein Light Chain 3 and Identification of Its Functional Subdomains J. Biol. Chem., July 1, 2005; 280(26): 24610 - 24617. [Abstract] [Full Text] [PDF]

				D. J. Klionsky The molecular machinery of autophagy: unanswered questions J. Cell Sci., January 1, 2005; 118(1): 7 - 18. [Abstract] [Full Text] [PDF]