ISSN:
1617-4623
Keywords:
Key wordsSchizosaccharomyces pombe
;
Signal transduction
;
Osmoregulation
;
Basic leucine zipper proteins
;
MAP kinase cascade
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract In Schizosaccharomyces pombe, recent studies have uncovered a set of putative transcription factors of the basic leucine zipper (bZIP) type (e.g., Atf1, Pcr1, Pap1), which function downstream of the Sty1 mitogen-activated protein kinase (MAPK) cascade which is involved in stress-activated signal transduction. Accordingly, a Δatf1 mutant is known to exhibit osmosensitivity for growth, since one of the targets of Atf1 is the gpd1 + gene, which is responsible for the osmoadaptive glycerol production mediated by the Sty1 MAPK cascade. During the course of our studies on the osmotic response in S. pombe, we found that growth of a Δatf1 mutant is highly sensitive to the level of Ca2+ ions in the medium (but less sensitive to Mg2+ and Na+ ions). This phenotype seemed to be relevant to the osmosensitivity, because an Δgpd1 mutant showed a similar phenotype. An attempt was therefore made to isolate multicopy suppressors of the calcium sensitivity exhibited by the Δatf1 cells. Among such suppressors were several bZIP factors, including two known proteins (Atf21 and Pcr1), and two new ones (named Atf31 and Zip1). These factors were characterized further, in comparison to Atf1, with special reference to the Sty1 MAPK signaling pathway.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004380050970
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