Purified anti-PME-1

Carboxymethylation of proteins is a highly conserved means of regulation in eukaryotic cells. The serine hydrolase protein phosphatase methylesterase-1 (PME-1) regulates the methylesterification state of protein phosphatase 2A (PP2A) and has been implicated in cancer and neurodegeneration disease. PME-1 is conserved from yeast to human and contains a motif found in lipases having a catalytic triad-activated serine as their active site nucleophile. Maturation of catalytic subunit of PP2A is under the surveillance of the PP2A methylesterase, PME1, which upon malfunction of PP2A biogenesis, prevents premature generation of the active C subunit and holoenzyme assembly by counteracting the untimely methylation of the C subunit. PME-1 has been recently identified as a protector of sustained ERK pathway activity in malignant gliomas. Mechanistically, PME-1 is shown to support ERK pathway signaling upstream of Raf, but downstream of growth factor receptors and protein kinase C. In malignant gliomas, PME-1 expression levels correlate with both ERK activity and cell proliferation in vivo.