QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online 27 June 2006
doi: 10.1242/jcs.03030

This Article Figures Only Full Text Full Text (PDF) Supplementary Material All Versions of this Article: jcs.03030v1 119/14/2995    most recent Alert me when this article is cited Alert me if a correction is posted 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 Grati, M. Articles by Wenthold, R. J. Search for Related Content PubMed PubMed Citation Articles by Grati, M. Articles by Wenthold, R. J. Social Bookmarking                         What's this?

Molecular determinants for differential membrane trafficking of PMCA1 and PMCA2 in mammalian hair cells

M'hamed Grati^1,*, Nisha Aggarwal¹, Emanuel E. Strehler² and Robert J. Wenthold^1,

¹ Laboratory of Neurochemistry, National Institute on Deafness and other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
² Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA

Author for correspondence (e-mail: wenthold{at}nidcd.nih.gov)

Accepted 2 May 2006

The plasma membrane Ca²⁺-ATPase-2 (PMCA2) is expressed in stereocilia of hair cells of the inner ear, whereas PMCA1 is expressed in the basolateral plasma membrane of hair cells. Both extrude excess Ca²⁺ from the cytosol. They are predicted to contain ten membrane-spanning segments, two large cytoplasmic loops as well as cytosolic N- and C-termini. Several isoform variants are generated for both PMCA1 and PMCA2 by alternative splicing, affecting their first cytosolic loop (A-site) and their C-terminal tail. To understand how these isoforms are differentially targeted in hair cells, we investigated their targeting regions and expression in hair cells. Our results show that a Leu-Ile motif in `b'-tail splice variants promotes PMCA1b and PMCA2b basolateral sorting in hair cells. Moreover, apical targeting of PMCA2 depends on the size of the A-site-spliced insert, suggesting that the conformation of the cytoplasmic loop plays a role in apical targeting.

Key words: Alternative splicing, Inner ear explant, Intracellular loop, Leucine-isoleucine signal, Stereocilia

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

This article has been cited by other articles:

				M. Brini and E. Carafoli Calcium Pumps in Health and Disease Physiol Rev, October 1, 2009; 89(4): 1341 - 1378. [Abstract] [Full Text] [PDF]

				M. Carmosino, I. Gimenez, M. Caplan, and B. Forbush Exon Loss Accounts for Differential Sorting of Na-K-Cl Cotransporters in Polarized Epithelial Cells Mol. Biol. Cell, October 1, 2008; 19(10): 4341 - 4351. [Abstract] [Full Text] [PDF]

				J. N. VanHouten, M. C. Neville, and J. J. Wysolmerski The Calcium-Sensing Receptor Regulates Plasma Membrane Calcium Adenosine Triphosphatase Isoform 2 Activity in Mammary Epithelial Cells: A Mechanism for Calcium-Regulated Calcium Transport into Milk Endocrinology, December 1, 2007; 148(12): 5943 - 5954. [Abstract] [Full Text] [PDF]

				F. Mammano, M. Bortolozzi, S. Ortolano, and F. Anselmi Ca2+ Signaling in the Inner Ear Physiology, April 1, 2007; 22(2): 131 - 144. [Abstract] [Full Text] [PDF]