In:
Eukaryotic Cell, American Society for Microbiology, Vol. 4, No. 6 ( 2005-06), p. 1041-1049
Abstract:
We demonstrate here that SAP155 encodes a negative modulator of K + efflux in the yeast Saccharomyces cerevisiae . Overexpression of SAP155 decreases efflux, whereas deletion increases efflux. In contrast, a homolog of SAP155 , called SAP185 , encodes a positive modulator of K + efflux: overexpression of SAP185 increases efflux, whereas deletion decreases efflux. Two other homologs, SAP4 and SAP190 , are without effect on K + homeostasis. Both SAP155 and SAP185 require the presence of SIT4 for function, which encodes a PP2A-like phosphatase important for the G 1 -S transition through the cell cycle. Overexpression of either the outwardly rectifying K + channel, Tok1p, or the putative plasma membrane K + /H + antiporter, Kha1p, increases efflux in both wild-type and sit4Δ strains. However, overexpression of the Na + -K + /H + antiporter, Nha1p, is without effect in a sit4 Δ strain, suggesting that Sit4p signals to Nha1p. In summary, the combined activities of Sap155p and Sap185p appear to control the function of Nha1p in K + homeostasis via Sit4p.
Type of Medium:
Online Resource
ISSN:
1535-9778
,
1535-9786
DOI:
10.1128/EC.4.6.1041-1049.2005
Language:
English
Publisher:
American Society for Microbiology
Publication Date:
2005
detail.hit.zdb_id:
2071564-X
SSG:
12
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