Disease relevance of POMT2

• We report heterozygous POMT2 mutations in an a girl with a milder phenotype characterized by mental retardation, microcephaly, hypertrophy of the quadriceps and calf muscles, and structural brain changes mostly affecting the posterior fossa [1].

High impact information on POMT2

• The requirement of an active enzyme complex of POMT1 and POMT2 suggests that the regulation of protein O-mannosylation is complex [2].
• Northern blot and reverse transcriptase polymerase chain reaction (RT-PCR) analyses revealed that rat Pomt1 and Pomt2 are expressed in all tissues but most strongly in testis [3].
• Two transcription-initiation sites were observed in rat Pomt2, resulting in two forms: a testis form and a somatic form [3].
• 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 [4].
• Our findings suggest that, as previously reported for POMT1 and FKRP, mutations in the POMT2 can also be associated with clinical heterogeneity [1].

Biological context of POMT2

• Mutations in POMT2 have so far only been reported in patients with Walker-Warburg phenotype [1].

Anatomical context of POMT2

• In situ hybridization histochemistry of rat brain revealed that Pomt1 and Pomt2 mRNA are coexpressed in neurons (dentate gyrus and CA1-CA3 region of the hippocampus and cerebellar Purkinje cells) [3].

Other interactions of POMT2

• Coexpression of POMT1 and POMT2 is required to show O-mannosylation activity [5].

Analytical, diagnostic and therapeutic context of POMT2

• Immunohistochemistry in muscle showed severely reduced levels of glycosylated alpha-DG, which is consistent with the postulated role for POMT2 in the O-mannosylation pathway [6].
• Molecular cloning and characterization of rat Pomt1 and Pomt2 [3].

References