title: Plasmodium falciparum GPI mannosyltransferase-III has novel signature sequence and is functional.
abstract: The glycosylphosphatidylinositol (GPI) anchors of Plasmodium falciparum are indispensable for parasite survival since merozoite surface proteins-1, -2, -4, -5, and -10, crucial for erythrocyte invasion, are GPI-anchored. Therefore, the GPI biosynthetic pathway can offer potential targets for novel anti-malarial drugs. Here, we characterized the putative P. falciparum PIG-B gene (PfPIGB) that encodes mannosyltransferase-III of GPI biosynthesis. PfPIGB mRNA is transcribed in a developmental stage specific manner. A protein corresponding to the expected size of PfPIG-B is expressed by the parasite and is localized in the endoplasmic reticulum. Treatment of parasites with PfPIG-B specific siRNA caused reduction in GPI synthesis, affecting the PIG-B specific GPI intermediate. These data demonstrate that PfPIG-B is functional and encodes mannosyltransferase-III of the parasite GPI biosynthesis. The parasite PfPIG-B is novel in that its signature sequence HKEHKI is unique and is only partially conserved as compared to HKEXRF signature motif of mammalian PIG-B enzymes.
authors.affiliation: Department of Biochemistry and Molecular Biology, Pennsylvania State University College of Medicine, Hershey, PA 17033, USA.
authors.forename: Suresh H
authors.initials: SH
authors.lastname: Basagoudanavar
authors.forename: Xiaorong
authors.initials: X
authors.lastname: Feng
authors.forename: Gowdahalli
authors.initials: G
authors.lastname: Krishnegowda
authors.forename: Arivalagan
authors.initials: A
authors.lastname: Muthusamy
authors.forename: D Channe
authors.initials: DC
authors.lastname: Gowda
mesh_terms: D000818:Animals; D001483:Base Sequence; D008364:Mannosyltransferases / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010963:Plasmodium falciparum / Q000235:genetics* / Q000378:metabolism*; D014018:Tissue Distribution
chemical_list: D008364:Mannosyltransferases