PCMT1 transfers CH3 from AdoMet to isoAsp to form MetAsp

Stable Identifier
R-HSA-5676966
Type
Reaction [transition]
Species
Homo sapiens
Compartment
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Protein-L-isoaspartate (D-aspartate) O-methyltransferase (PCMT1, PIMT EC 2.1.1.77) transfers the methyl group from S-adenosyl-L-methionine (AdoMet) to the alpha side-chain carboxyl group of L-isoaspartyl and D-aspartatyl amino acids (Murray & Clarke 1986, Johnson et al. 1987, Galletti et al. 1988, Lowenson & Clarke 1992, The resulting methyl ester (MetAsp) undergoes spontaneous transformation to L-succinimide, which spontaneously hydrolyses to generates L-aspartyl residues or L-isoaspartyl residues. This repair process helps to maintain overall protein integrity. When PCMT1 is not present in cells, the abnormal aspartyl residues accumulate. Pcmt1 knockout mice exhibit fatal progressive epilepsy (Yamamoto et al. 1998).

Literature References
PubMed ID Title Journal Year
3624258 Partial repair of deamidation-damaged calmodulin by protein carboxyl methyltransferase

Johnson, BA, Langmack, EL, Aswad, DW

J. Biol. Chem. 1987
7592526 Characterization of three cDNAs encoding two isozymes of an isoaspartyl protein carboxyl methyltransferase from human erythroid leukemia cells

Takeda, R, Mizobuchi, M, Murao, K, Sato, M, Takahara, J

J. Biochem. 1995
Participants
Participant Of
hasEvent
Catalyst Activity
Catalyst Activity
Title
protein-L-isoaspartate (D-aspartate) O-methyltransferase activity of PCMT1 [cytosol]
Physical Entity
Activity
Orthologous Events
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Created