|Protein Name||Protein phosphatase 1 regulatory subunit 7|
|Amino Acid Lenth||360|
|Protein Existence Status||Reviewed: Experimental evidence at protein level|
|Protein Function||serine/threonine phosphatase that regulates diverse, essential cellular processes such as cell cycle progression, protein synthesis, muscle contraction, carbohydrate metabolism, transcription and neuronal signaling;|
|Biochemical Properties||specific inhibitory proteins, such as inhibitor-2 and DARPP-32, bind and block the protein phosphatase1 catalytic active site, which contains two metal ions (Mn2+), that are required for the enzymatic activity; The catalytic site of PP1 is at the intersection of three potential substrate binding regions, the hydrophobic, acidic and C-terminal grooves; two Mn2+ ions bind the PP1 active site in solution; apo form of the enzyme is only stable for short periods of time before it begins to form soluble aggregates; prominent inhibitors are microcystin, nodularin , calyculin A, tautomycin and okadaic acid; PP1c is also specifically inhibited by small acidic thermostable proteins, such as inhibitor-1, inhibitor-2, NIPPs (1), and IP|
|Significance in milk||could adjust the development and lactation of mammary gland|
|PTMs||phosphorylated - catalytic subunit of protein phosphatase 2A(PP2Ac) is phosphorylated by receptor and Src family tyrosine kinases on Tyr307,upstream of its carboxyl terminus (Leu309); In vitro, PP2Ac phosphorylation is found to be on Thr residue(s) catalyzed by the autophosphorylation-activated protein kinas ; PP2Ac is methylated on Leu309 by a novel type of carboxyl protein methyltransferase|
|Significance of PTMs||phosphorylation - (PP2Ac) phosphorylation on Tyr307 and Leu309 suppresses its activity; In vitro, PP2Ac phosphorylation on Thr residue(s) inactivates the enzyme|
|Bibliography||1. Favre, B., Turowski, P. and Hemmings, B. A. (1997) ‘Differential Inhibition and Posttranslational Modification of Protein Phosphatase 1 and 2A in MCF7 Cells Treated with Calyculin-A, Okadaic Acid, and Tautomycin’, Journal of Biological Chemistry, 272(21), pp. 13856–13863. doi: 10.1074/jbc.272.21.13856. |
2. Hou, J. et al. (2017) ‘Detection and comparison of microRNAs in the caprine mammary gland tissues of colostrum and common milk stages’, BMC Genetics, 18(1), p. 38. doi: 10.1186/s12863-017-0498-2.
3. Dancheck, B. et al. (2011) ‘Molecular Investigations of the Structure and Function of the Protein Phosphatase 1−Spinophilin−Inhibitor 2 Heterotrimeric Complex’, Biochemistry, 50(7), pp. 1238–1246. doi: 10.1021/bi101774g.
4. Kelker, M. S., Page, R. and Peti, W. (2009) ‘Crystal Structures of Protein Phosphatase-1 Bound to Nodularin-R and Tautomycin: A Novel Scaffold for Structure-based Drug Design of Serine/Threonine Phosphatase Inhibitors’, Journal of Molecular Biology, 385(1), pp. 11–21. doi: 10.1016/j.jmb.2008.10.053.
5. Kita, A. et al. (2002) ‘Crystal structure of the complex between calyculin A and the catalytic subunit of protein phosphatase 1.’, Structure (London, England : 1993), 10(5), pp. 715–24. doi: 10.1016/s0969-2126(02)00764-5.
6. Maynes, J. T. et al. (2001) ‘Crystal Structure of the Tumor-promoter Okadaic Acid Bound to Protein Phosphatase-1’, Journal of Biological Chemistry, 276(47), pp. 44078–44082. doi: 10.1074/jbc.M107656200.