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

J. Biol. Chem., Vol. 281, Issue 30, 20974-20982, July 28, 2006

This Article Full Text Full Text (PDF) All Versions of this Article: 281/30/20974    most recent M601401200v1 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 Siddiqi, S. A. Articles by Mansbach, C. M. Search for Related Content PubMed PubMed Citation Articles by Siddiqi, S. A. Articles by Mansbach, C. M., II Social Bookmarking                      What's this?

The Identification of a Novel Endoplasmic Reticulum to Golgi SNARE Complex Used by the Prechylomicron Transport Vesicle^*

Shadab A. Siddiqi, Shahzad Siddiqi, James Mahan, Kiffany Peggs, Fred S. Gorelick^¶||, and Charles M. Mansbach, II¹

From the Division of Gastroenterology, University of Tennessee Health Science Center, Memphis, Tennessee 38163 and Veterans Affairs Medical Center, Memphis, Tennessee 38104, the ^¶Department of Medicine, Veterans Affairs Healthcare, and ^||Yale University School of Medicine, New Haven, Connecticut 06516

Dietary long chain fatty acids are absorbed in the intestine, esterified to triacylglycerol, and packaged in the unique lipoprotein of the intestine, the chylomicron. The rate-limiting step in the transit of chylomicrons through the enterocyte is the exit of chylomicrons from the endoplasmic reticulum in prechylomicron transport vesicles (PCTV) that transport chylomicrons to the cis-Golgi. Because chylomicrons are 250 nm in average diameter and lipid absorption is intermittent, we postulated that a unique SNARE pairing would be utilized to fuse PCTV with their target membrane, cis-Golgi. PCTV loaded with [³H]triacylglycerol were incubated with cis-Golgi and were separated from the Golgi by a sucrose step gradient. PCTV-chylomicrons acquire apolipoprotein-AI (apoAI) only after fusion with the Golgi. PCTV became isodense with Golgi upon incubation and were considered fused when their cargo chylomicrons acquired apoAI but docked when they did not. PCTV, docked with cis-Golgi, were solubilized in 2% Triton X-100, and proteins were immunoprecipitated using VAMP7 or rBet1 antibodies. In both cases, a 112-kDa complex was identified in nonboiled samples that dissociated upon boiling. The constituents of the complex were VAMP7, syntaxin 5, vti1a, and rBet1. Antibodies to each SNARE component significantly inhibited fusion of PCTV with cis-Golgi. Membrin, Sec22b, and Ykt6 were not found in the 112-kDa complex. We conclude that the PCTV-cis-Golgi SNARE complex is composed of VAMP7, syntaxin 5, Bet1, and vti1a.

Received for publication, February 14, 2006 , and in revised form, May 23, 2006.

^* This study was supported by NIDDK, National Institutes of Health (NIH), Grants DK38760 (to C. M. M.) and DK54201 (to F. S. G.) and NIH Medical Student Research Program Grant T35DK07405. The Stout Neuroscience Laboratory was supported by NIH Grant RR1052 and National Science Foundation Grant DB1960633, a Veterans Administration Senior Career Development Award (to F. S. G.), and Office of Research and Development (R & D) Medical Research Service, Department of Veteran Affairs, research funds (to C. M. M. and F. S. G.). 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.

¹ To whom correspondence should be addressed: Division of Gastroenterology, the University of Tennessee Health Science Center, 920 Madison Ave., Suite 240, Memphis, TN 38163. Tel.: 901-448-5813; Fax: 901-448-7091; E-mail: cmansbach{at}utmem.edu.

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

This article has been cited by other articles:

				J. Storch, Y. X. Zhou, and W. S. Lagakos Metabolism of apical versus basolateral sn-2-monoacylglycerol and fatty acids in rodent small intestine J. Lipid Res., August 1, 2008; 49(8): 1762 - 1769. [Abstract] [Full Text] [PDF]

				S. A. Siddiqi and C. M. Mansbach II PKC{zeta}-mediated phosphorylation controls budding of the pre-chylomicron transport vesicle J. Cell Sci., July 15, 2008; 121(14): 2327 - 2338. [Abstract] [Full Text] [PDF]

				E. M. Pasini, M. Kirkegaard, D. Salerno, P. Mortensen, M. Mann, and A. W. Thomas Deep Coverage Mouse Red Blood Cell Proteome: A First Comparison with the Human Red Blood Cell Mol. Cell. Proteomics, July 1, 2008; 7(7): 1317 - 1330. [Abstract] [Full Text] [PDF]

				C. M. Mansbach II and F. Gorelick Development and Physiological Regulation of Intestinal Lipid Absorption. II. Dietary lipid absorption, complex lipid synthesis, and the intracellular packaging and secretion of chylomicrons Am J Physiol Gastrointest Liver Physiol, October 1, 2007; 293(4): G645 - G650. [Abstract] [Full Text] [PDF]

				D. D. Black Development and Physiological Regulation of Intestinal Lipid Absorption. I. Development of intestinal lipid absorption: cellular events in chylomicron assembly and secretion Am J Physiol Gastrointest Liver Physiol, September 1, 2007; 293(3): G519 - G524. [Abstract] [Full Text] [PDF]

				V. M. Olkkonen and E. Ikonen When intracellular logistics fails - genetic defects in membrane trafficking J. Cell Sci., December 15, 2006; 119(24): 5031 - 5045. [Abstract] [Full Text] [PDF]