Functional analysis of the Neurospora crassa PZL-1 protein phosphatase by expression in budding and fission yeast.
The gene pzl-1 from the filamentous fungus Neurospora crassa encodes a putative Ser/Thr protein phosphatase that is reminiscent of the Ppz1/Ppz2 and Pzh1 phosphatases from Saccharomyces cerevisiae and Schizosaccharomyces pombe, respectively. The entire PZL-1 protein, as well as its carboxyl-terminal domain, have been expressed in Escherichia coli as active protein phosphatases. To characterize its cellular role, PZL-1 was also expressed in Sz. pombe and in S. cerevisiae. Expression of PZL-1 in S. cerevisiae from the PPZ1 promoter was able to rescue the altered sensitivity to caffeine and lithium ions of a ppz1 strain. Furthermore, high copy number expression of PZL-1 alleviated the lytic phenotype of a S. cerevisiae slt2/mpk1 mitogen-activated protein (MAP) kinase mutant, similarly to that described for PPZ1, and mimicked the effects of high levels of Ppz1 on cell growth. Expression of PZL-1 in fission yeast from a weak version of the nmt1 promoter fully rescued the growth defect of a pzh1Delta strain in high potassium, but only partially complemented the sodium-hypertolerant phenotype. Strong overexpression of the N. crassa phosphatase in Sz. pombe affected cell growth and morphology. Therefore, PZL-1 appears to fulfil every known function carried out by its S. cerevisiae counterpart, despite the marked divergence in sequence within their NH(2)-terminal moieties.
Vissi
E
E
Department of Medical Chemistry, Faculty of Medicine, Medical and Health Science Centre, University of Debrecen, H-4026 Debrecen, Hungary.
Clotet
J
J
de Nadal
E
E
Barceló
A
A
Bakó
E
E
Gergely
P
P
Dombrádi
V
V
Ariño
J
J
D020134:Catalytic Domain; D002453:Cell Cycle; D018797:Cell Cycle Proteins; D003001:Cloning, Molecular; D004926:Escherichia coli; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D009492:Neurospora crassa / Q000201:enzymology* / Q000235:genetics; D010749:Phosphoprotein Phosphatases / Q000235:genetics* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D012568:Schizosaccharomyces / Q000235:genetics*
D018797:Cell Cycle Proteins; D005656:Fungal Proteins; C092936:SIS2 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C075119:PPZ1 protein, S cerevisiae; D010749:Phosphoprotein Phosphatases