Display Settings:

Format

Send to:

Choose Destination
Glycobiology. 2002 Nov;12(11):771-83.

Characterization of POMT2, a novel member of the PMT protein O-mannosyltransferase family specifically localized to the acrosome of mammalian spermatids.

Author information

  • 1Lehrstuhl für Zellbiologie und Pflanzenphysiologie, Universität Regensburg, 93040 Regensburg, Germany.

Abstract

Over the past few years it has emerged that O-mannosyl glycans are not restricted to yeasts and fungi but are also present in higher eukaryotes, including humans. They play a substantial role in the onset of muscular dystrophy and neuronal migration disorders, like muscle-eye-brain disease. Protein O-mannosyltransferase genes (PMTs) are evolutionarily conserved from yeast to human; however, little is known about these enzymes in higher eukaryotes. In this study, we cloned the first PMT2 subfamily members from human (hPOMT2), mouse (mPomt2), and Drosophila (DmPOMT2). A detailed characterization of the mammalian POMT2, with emphasis on mouse Pomt2, shows that mammalian POMT2 is predominantly expressed in testis tissue. Due to differential transcription initiation of the mPomt2 gene, two distinct mRNA species that vary in length are formed. The shorter transcript is present in all somatic tissues examined. Expression of the corresponding hPOMT2 cDNA in mammalian cells identified POMT2 as an integral membrane protein of the endoplasmic reticulum with an apparent molecular weight of 83 kDa. The longer mPomt2 transcript is restricted to testis and encodes a testis-specific mPOMT2 protein isoform. Using in situ hybridization and immunolocalization, we demonstrate that in testis tissue mPOMT2 localizes to maturing spermatids and is abundant within the acrosome, a sperm-specific organelle essential for fertilization. Our data suggest a novel and specific role for the putative protein O-mannosyltransferase POMT2 in the maturation and/or function of sperm in mammals.

PMID:
12460945
[PubMed - indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire
    Loading ...
    Write to the Help Desk