RRC ID 894
Author Mitsui K, Ochi F, Nakamura N, Doi Y, Inoue H, Kanazawa H.
Title A novel membrane protein capable of binding the Na+/H+ antiporter (Nha1p) enhances the salinity-resistant cell growth of Saccharomyces cerevisiae.
Journal J. Biol. Chem.
Abstract The Na+/H+ antiporter Nha1p of Saccharomyces cerevisiae plays an important role in maintaining intracellular pH and Na+ homeostasis. Nha1p has a two-domain structure composed of integral membrane and hydrophilic tail regions. Overexpression of a peptide of approximately 40 residues (C1+C2 domains) that is localized in the juxtamembrane area of its cytoplasmic tail caused cell growth retardation in highly saline conditions, possibly by decreasing Na+/H+ antiporter activity. A multicopy suppressor gene of this growth retardation was identified from a yeast genome library. The clone encodes a novel membrane protein denoted as COS3 in the genome data base. Overexpression or deletion of COS3 increases or decreases salinity-resistant cell growth, respectively. However, in nha1Delta cells, overexpression of COS3 alone did not suppress the growth retardation. Cos3p and a hydrophilic portion of Cos3p interact with the C1+C2 peptide in vitro, and Cos3p is co-precipitated with Nha1p from yeast cell extracts. Cos3p-GFP mainly resides at the vacuole, but overexpression of Nha1p caused a portion of the Cos3p-GFP proteins to shift to the cytoplasmic membrane. These observations suggest that Cos3p is a novel membrane protein that can enhance salinity-resistant cell growth by interacting with the C1+C2 domain of Nha1p and thereby possibly activating the antiporter activity of this protein.
Volume 279(13)
Pages 12438-47
Published 2004-3-26
DOI 10.1074/jbc.M310806200
PII M310806200
PMID 14718542
MeSH Amino Acid Sequence Cation Transport Proteins / chemistry* Cation Transport Proteins / metabolism* Cell Division Cell Membrane / metabolism* Centrifugation, Density Gradient Cytoplasm / metabolism DNA Primers / pharmacology Dose-Response Relationship, Drug Gene Library Genes, Dominant Genes, Fungal Green Fluorescent Proteins Luminescent Proteins / metabolism Membrane Proteins / chemistry* Membrane Proteins / metabolism* Membrane Proteins / physiology* Molecular Sequence Data Open Reading Frames Peptides / chemistry Plasmids / metabolism Precipitin Tests Protein Binding Protein Structure, Tertiary Saccharomyces cerevisiae / metabolism* Saccharomyces cerevisiae Proteins / chemistry* Saccharomyces cerevisiae Proteins / physiology* Sequence Homology, Amino Acid Sodium Chloride / pharmacology* Sodium-Hydrogen Exchangers / chemistry* Sodium-Hydrogen Exchangers / metabolism* Subcellular Fractions Time Factors
IF 4.011
Times Cited 16
Yeast BY4849(W303-1B)