| First Author | Kutuzov MA | Year | 2002 |
| Journal | Biochem Biophys Res Commun | Volume | 293 |
| Issue | 3 | Pages | 1047-52 |
| PubMed ID | 12051765 | Mgi Jnum | J:282693 |
| Mgi Id | MGI:6383775 | Doi | 10.1016/S0006-291X(02)00338-8 |
| Citation | Kutuzov MA, et al. (2002) Protein Ser/Thr phosphatases PPEF interact with calmodulin. Biochem Biophys Res Commun 293(3):1047-52 |
| abstractText | Regulation of protein dephosphorylation by cytoplasmic Ca(2+) levels and calmodulin (CaM) is well established and considered to be mediated solely by calcineurin. Yet, recent identification of protein phosphatases with EF-hand domains (PPEF/rdgC) point to the existence of another group of Ca(2+)-dependent protein phosphatases. We have recently hypothesised that PPEF/rdgC phosphatases might possess CaM-binding sites of the IQ-type in their N-terminal domains. We now employed yeast two-hybrid system and surface plasmon resonance (SPR) to test this hypothesis. We found that entire human PPEF2 interacts with CaM in the in vivo tests and that its N-terminal domain binds to CaM in a Ca(2+)-dependent manner with nanomolar affinity in vitro. The fragments corresponding to the second exons of PPEF1 and PPEF2, containing the IQ motifs, are sufficient for specific Ca(2+)-dependent interaction with CaM both in vivo and in vitro. These findings demonstrate the existence of mammalian CaM-binding protein Ser/Thr phosphatases distinct from calcineurin and suggest that the activity of PPEF phosphatases may be controlled by Ca(2+) in a dual way: via C-terminal Ca(2+)-binding domain and via interaction of the N-terminal domain with CaM. |
