The terminal phase of cytokinesis in the Caenorhabditis elegans early embryo requires protein glycosylation.
RNA interference (RNAi) was used to characterize the requirement of protein glycosylation for cell membrane stability during cytokinesis in the early embryo. This screen targeted 13 enzymes or components of polypeptide sugar transferases that initiate either N-glycosylation or three different pathways of O-glycosylation. RNAi of genes in the mucin-type and epidermal growth factor-fringe glycosylation pathways did not affect cytokinesis. However, embryos deficient in N-glycosylation exhibited a variable inability to complete cytokinesis. The most potent block in early embryonic cell division was obtained by RNAi of the polypeptide xylose transferase (ppXyl-T), which is required to initiate the proteoglycan modification pathway. Two generations of ppXyl-T RNAi-feeding treatment reduced the body size, mobility, brood size, and life span of adult animals. Embryos escaping ppXyl-T and Gal-T2 RNAi lethality develop to adulthood but have cytokinesis-deficient offspring, suggesting that glycosyltransferases in the proteoglycan pathway are maternal proteins in the early embryo. Gal-T2::GFP fusions and anti-Gal-T2 antibodies revealed a perinuclear staining pattern, consistent with the localization of the Golgi apparatus. RNAi in green fluorescent protein (GFP)-tagged strains to follow tubulin, PIE-1, and chromatin showed that deficient proteoglycan biosynthesis uncouples the stability of newly formed cell membranes from cytokinesis, whereas cleavage furrow initiation, mitotic spindle function, karyokinesis, and partitioning of intrinsic components are intact.
Department of Biochemistry and Biophysics, Center for Oral Biology, University of Rochester Medical Center, Rochester, NY 14642, USA.
Huan
H
Wang
Anne
A
Spang
Mark A
MA
Sullivan
Jennifer
J
Hryhorenko
Fred K
FK
Hagen
D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology* / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism*; D002462:Cell Membrane; D048749:Cytokinesis / Q000502:physiology*; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000378:metabolism*; D006023:Glycoproteins / Q000096:biosynthesis / Q000378:metabolism*; D006031:Glycosylation; D016695:Glycosyltransferases / Q000235:genetics* / Q000378:metabolism; D008938:Mitosis / Q000502:physiology; D008969:Molecular Sequence Data; D011509:Proteoglycans / Q000378:metabolism; D034622:RNA Interference; D011994:Recombinant Proteins / Q000235:genetics; D008941:Spindle Apparatus / Q000502:physiology
D029742:Caenorhabditis elegans Proteins; D006023:Glycoproteins; D011509:Proteoglycans; D011994:Recombinant Proteins; D016695:Glycosyltransferases