Identification and localization of the sod2 gene product in fission yeast.
Sod2, the Na+/H+ antiporter of the fission yeast Schizosaccharomyces pombe, was identified by addition of a hemagglutinin tag to the carboxyl terminus of the protein. The tagged protein was expressed in the sod2-deficient strain of S. pombe. Transformants retained tolerance to lithium (1-10 mM) at external pH values from 3.5 to 6.5. Both Na+-dependent proton uptake and active sodium extrusion were also restored in transformed cells, suggesting that a functional antiporter was present. The protein was present in a membrane fraction. In SDS PAGE it migrated as a single 47 kDa band. The protein could be efficiently solubilized with the non-ionic detergent, dodecyl maltoside. Immunofluorescent microscopy revealed an asymmetric distribution with preferable accumulation in polar tip areas. The results are the first identification and localization of the Na+/H+ exchanger in yeast cells.
Dibrov
P
P
Department of Pediatrics, University of Alberta, Edmonton, Canada.
Smith
J J
JJ
Young
P G
PG
Fliegel
L
L
D019084:Fluorescent Antibody Technique, Indirect; D005656:Fungal Proteins / Q000032:analysis* / Q000737:chemistry / Q000235:genetics; D015870:Gene Expression; D006388:Hemagglutinins / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012568:Schizosaccharomyces / Q000737:chemistry* / Q000235:genetics; D016324:Sequence Tagged Sites; D017923:Sodium-Hydrogen Exchangers / Q000032:analysis* / Q000737:chemistry / Q000235:genetics
D005656:Fungal Proteins; D006388:Hemagglutinins; D011993:Recombinant Fusion Proteins; D017923:Sodium-Hydrogen Exchangers