Plasmodium falciparum protein phosphatase type 1 functionally complements a glc7 mutant in Saccharomyces cerevisiae

Document Type

Journal Article

Publication Date

1-1-2002

Journal

International Journal for Parasitology

Volume

32

Issue

6

DOI

10.1016/S0020-7519(02)00007-3

Keywords

Calyculin A; Complementation; glc7; Hyperphosphorylation; Plasmodium falciparum; Protein phosphatase type 1; Saccharomyces cerevisiae

Abstract

We have identified a new homologue of protein phosphatase type 1 from Plasmodium falciparum, designated PfPP1, which shows 83-87% sequence identity with yeast and mammalian PP1s at the amino acid level. The PfPP1 sequence is strikingly different from all other P. falciparum Ser/Thr phosphatases cloned so far. The deduced 304 amino acid sequence revealed the signature sequence of Ser/Thr phosphatase LRGNHE, and two putative protein kinase C and five putative casein kinase II phosphorylation sites. Calyculin A, a potent inhibitor of Ser/Thr phosphatase 1 and 2A showed hyperphosphorylation of a 51 kDa protein among other parasite proteins. Okadaic acid on the other hand, was without any effect suggesting that PP1 activity might predominate over PP2A activity in intra-erythrocytic P. falciparum. Complementation studies showed that PfPP1 could rescue low glycogen phenotype of Saccharomyces cerevisiae glc7 (PP1-) mutant, strongly suggesting functional interaction of PfPP1 and yeast proteins involved in glycogen metabolism. © 2002 Australian Society for Parasitology Inc. Published by Elsevier Science Ltd. All rights reserved.

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