| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
J. Biol. Chem., Vol. 278, Issue 45, 43991-44000, November 7, 2003
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
From the Department of Biochemistry and Molecular Biology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
The serotonin transporter (SERT) is an oligomeric glycoprotein with two sialic acid residues on each of two complex oligosaccharide molecules. In this study, we investigated the contribution of N-glycosyl modification to the structure and function of SERT in two model systems: wild-type SERT expressed in sialic acid-defective Lec Chinese hamster ovary (CHO) cells and a mutant form (after site-directed mutagenesis of Asn-208 and Asn-217 to Gln) of SERT, QQ, expressed in parental CHO cells. In both systems, SERT monomers required modification with both complex oligosaccharide residues to associate with each other and to function in homo-oligomeric forms. However, defects in sialylated N-glycans did not alter surface expression of the SERT protein. Furthermore, in heterologous (CHO and Lec) and endogenous (placental choriocarcinoma JAR cells) expression systems, we tested whether glycosyl modification also manipulates the hetero-oligomeric interactions of SERT, specifically with myosin IIA. SERT is phosphorylated by cGMP-dependent protein kinase G through interactions with anchoring proteins, and myosin is a protein kinase G-anchoring protein. A physical interaction between myosin and SERT was apparent; however, defects in sialylated N-glycans impaired association of SERT with myosin as well as the stimulation of the serotonin uptake function in the cGMP-dependent pathway. We propose that sialylated N-glycans provide a favorable conformation to SERT that allows the transporter to function most efficiently via its protein-protein interactions.
Received for publication, June 16, 2003 , and in revised form, August 25, 2003.
* This work was supported by grants from the Rockefeller Brothers Funds, the National Alliance for Research on Schizophrenia and Depression, and the Arkansas Tobacco Settlement (to F. 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 and Molecular Biology, College of Medicine, University of Arkansas for Medical Sciences, 4301 West Markham St., 516, Little Rock, AR 72205. Tel.: 501-526-6488; Fax: 501-686-8169; E-mail: kilicfusun{at}uams.edu.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
 |
|
  B. A. Ahmed, B. C. Jeffus, S. I. A. Bukhari, J. T. Harney, R. Unal, V. V. Lupashin, P. van der Sluijs, and F. Kilic Serotonin Transamidates Rab4 and Facilitates Its Binding to the C Terminus of Serotonin Transporter J. Biol. Chem., April 4, 2008; 283(14): 9388 - 9398. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W. Jiang, O. Prokopenko, L. Wong, M. Inouye, and O. Mirochnitchenko IRIP, a New Ischemia/Reperfusion-Inducible Protein That Participates in the Regulation of Transporter Activity Mol. Cell. Biol., August 1, 2005; 25(15): 6496 - 6508. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L.-B. Li, N. Chen, S. Ramamoorthy, L. Chi, X.-N. Cui, L. C. Wang, and M. E. A. Reith The Role of N-Glycosylation in Function and Surface Trafficking of the Human Dopamine Transporter J. Biol. Chem., May 14, 2004; 279(20): 21012 - 21020. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| All ASBMB Journals | Molecular and Cellular Proteomics |
| Journal of Lipid Research | ASBMB Today |
