| Autor: |
LONGIN, Sari, JORDENS, Jan, MARTENS, Ellen, STEVENS, Ilse, JANSSENS, Veerle, RONDELEZ, Evelien, DE BAERE, Ivo, DERUA, Rita, WAELKENS, Etienne, GORIS, Jozef, VAN HOOF, Christine |
| Zdroj: |
Biochemical Journal; May 2004, Vol. 380 Issue: 1 p111-119, 9p |
| Abstrakt: |
We have described recently the purification and cloning of PP2A (protein phosphatase 2A) leucine carboxylmethyltransferase. We studied the purification of a PP2A-specific methylesterase that co-purifies with PP2A and found that it is tightly associated with an inactive dimeric or trimeric form of PP2A. These inactive enzyme forms could be reactivated as Ser/Thr phosphatase by PTPA (phosphotyrosyl phosphatase activator of PP2A). PTPA was described previously by our group as a protein that stimulates the in vitro phosphotyrosyl phosphatase activity of PP2A; however, PP2A-specific methyltransferase could not bring about the activation. The PTPA activation could be distinguished from the Mn2+ stimulation observed with some inactive forms of PP2A, also found associated with PME-1 (phosphatase methylesterase 1). We discuss a potential new function for PME-1 as an enzyme that stabilizes an inactivated pool of PP2A. |
| Databáze: |
Supplemental Index |
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