High impact information on PMT4

• O-Glycosylation of Axl2/Bud10p by Pmt4p is required for its stability, localization, and function in daughter cells [1].
• PMT4 encodes a protein mannosyl transferase (pmt) required for O-linked glycosylation of some secretory and cell surface proteins (Immervoll, T., M. Gentzsch, and W. Tanner. 1995. Yeast. 11:1345-1351) [1].
• We found that a and alpha mutants defective in the previously identified PMT4 gene exhibit unipolar, rather than axial budding: mother cells choose axial bud sites, but daughter cells do not [1].
• We demonstrate that Axl2/Bud10p, which is required for the axial budding pattern, is an O-linked glycoprotein and is incompletely glycosylated, unstable, and mislocalized in cells lacking PMT4 [1].
• In cells lacking PMT4, encoding a mannosyltransferase involved in the initial step of O-glycosylation, Fus1p was not glycosylated and accumulated in late Golgi structures [2].

Biological context of PMT4

• The pmt4 null mutant the pmt3 pmt4 double null mutant, but not pmt3 null mutant, showed a significant shift of chitinase due to under glycosylation of the enzyme [3].
• The triple disruption pmt2 pmt3 pmt4 and the quadruple disruption result in a lethal phenotype [3].
• The PMT family is phylogenetically classified into PMT1, PMT2, and PMT4 subfamilies, which differ in protein substrate specificity [4].
• A search of the Schizosaccharomyces pombe genome database revealed a total of three O-glycoside mannosyltransferase homologs (ogm1+, ogm2+, and ogm4+), closely related to Saccharomyces cerevisiae PMT1, PMT2, and PMT4 [5].

Other interactions of PMT4

• Northern blot analysis showed a single mRNA transcript of PMT3 and PMT4 of 2.8 kb [3].
• Overexpression of AXL2 can partially restore proper bud-site selection to pmt4 mutants [1].

Analytical, diagnostic and therapeutic context of PMT4

• Sequence analysis of the predicted protein revealed the highest similarity to Schizosaccharomyces pombe Pmt and to Pmt4p of Saccharomyces cerevisiae [6].

References