title: Essential role of YlMPO1, a novel Yarrowia lipolytica homologue of Saccharomyces cerevisiae MNN4, in mannosylphosphorylation of N- and O-linked glycans.
abstract: Mannosylphosphorylation of N- and O-glycans, which confers negative charges on the surfaces of cells, requires the functions of both MNN4 and MNN6 in Saccharomyces cerevisiae. To identify genes relevant to mannosylphosphorylation in the dimorphic yeast Yarrowia lipolytica, the molecular functions of five Y. lipolytica genes showing significant sequence homology with S. cerevisiae MNN4 and MNN6 were investigated. A set of mutant strains in which Y. lipolytica MNN4 and MNN6 homologues were deleted underwent glycan structure analysis. In contrast to S. cerevisiae MNN4 (ScMNN4), the Y. lipolytica MNN4 homologue, MPO1 (YlMPO1), encodes a protein that lacks the long KKKKEEEE repeat domain at its C terminus. Moreover, just a single disruption of YlMPO1 resulted in complete disappearance of the acidic sugar moiety in both the N- and O-linked glycan profiles. In contrast, even quadruple disruption of all ScMNN6 homologues, designated YlKTR1, YlKTR2, YlKTR3, and YlKTR4, resulted in no apparent reduction in acidic sugar moieties. These findings strongly indicate that YlMpo1p performs a significant role in mannosylphosphorylation in Y. lipolytica with no involvement of the Mnn6p homologues. Mutant strains harboring the YlMPO1 gene disruption may serve as useful platforms for engineering Y. lipolytica glycosylation pathways for humanized glycans without any yeast-specific acidic modifications.
authors.affiliation: Department of Life Science, College of Natural Science, Chung-Ang University, Seoul 156-756, South Korea.
authors.forename: Jeong-Nam
authors.initials: JN
authors.lastname: Park
authors.forename: Yunkyoung
authors.initials: Y
authors.lastname: Song
authors.forename: Seon Ah
authors.initials: SA
authors.lastname: Cheon
authors.forename: Ohsuk
authors.initials: O
authors.lastname: Kwon
authors.forename: Doo-Byoung
authors.initials: DB
authors.lastname: Oh
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Jigami
authors.forename: Jeong-Yoon
authors.initials: JY
authors.lastname: Kim
authors.forename: Hyun Ah
authors.initials: HA
authors.lastname: Kang
mesh_terms: D001483:Base Sequence; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism*; D005800:Genes, Fungal; D006031:Glycosylation; D008358:Mannose / Q000378:metabolism; D008364:Mannosyltransferases; D008565:Membrane Proteins / Q000378:metabolism; D010766:Phosphorylation; D016133:Polymerase Chain Reaction; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D017385:Sequence Homology; D025062:Yarrowia / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*
chemical_list: D004271:DNA, Fungal; D005656:Fungal Proteins; C105147:MNN4 protein, S cerevisiae; D008565:Membrane Proteins; D011134:Polysaccharides; D029701:Saccharomyces cerevisiae Proteins; C525358:MNN6 protein, S cerevisiae; D008364:Mannosyltransferases; D008358:Mannose