title: Plasmodium falciparum protein phosphatase type 1 functionally complements a glc7 mutant in 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 51kDa 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.
authors.affiliation: Johns Hopkins Malaria Research Institute, The W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA.
authors.forename: Mrinal K
authors.initials: MK
authors.lastname: Bhattacharyya
authors.forename: Zheng
authors.initials: Z
authors.lastname: Hong
authors.forename: Darin
authors.initials: D
authors.lastname: Kongkasuriyachai
authors.forename: Nirbhay
authors.initials: N
authors.lastname: Kumar
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D003001:Cloning, Molecular; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics*; D018628:Gene Dosage; D005816:Genetic Complementation Test; D006801:Humans; D008969:Molecular Sequence Data; D010749:Phosphoprotein Phosphatases / Q000737:chemistry / Q000235:genetics*; D010963:Plasmodium falciparum / Q000201:enzymology / Q000235:genetics*; D016133:Polymerase Chain Reaction; D054645:Protein Phosphatase 1; D015800:Protozoan Proteins / Q000235:genetics; D016053:RNA, Protozoan / Q000737:chemistry / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D017386:Sequence Homology, Amino Acid
chemical_list: D016054:DNA, Protozoan; D005656:Fungal Proteins; D015800:Protozoan Proteins; D016053:RNA, Protozoan; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1