Skip to main content
NCBI home page
Biochemical Journal logoLink to Biochemical Journal
. 1988 Mar 15;250(3):659–663. doi: 10.1042/bj2500659

The modulator protein dissociates the catalytic subunit of hepatic protein phosphatase G from glycogen.

M Bollen 1, W Stalmans 1
PMCID: PMC1148909  PMID: 2839141

Abstract

1. The phosphorylase phosphatase and glycogen-synthase phosphatase activities associated with the glycogen particles from rat liver were progressively inhibited by incubation with modulator protein. However, the phosphorylase phosphatase activity of the catalytic subunit was entirely recovered after destruction of the modulator and the regulatory subunit(s) by trypsin. 2. Inhibition of protein phosphatase G by modulator was associated with a translocation of the phosphorylase phosphatase activity (measured after incubation with trypsin) from glycogen to the soluble fraction. The degree of inhibition of phosphatase G corresponded closely to the extent to which the phosphorylase phosphatase activity was released from the glycogen particles. Incubation of glycogen-free protein phosphatase G with modulator did not change the affinity of the enzyme for added glycogen, but decreased the amount of phosphatase that could be bound to glycogen. 3. The phosphorylase phosphatase activity that was released from the glycogen particles by modulator migrated on gel filtration as a complex (Mr 106,000) of the catalytic subunit with modulator. Phosphorylase phosphatase activity could be transferred from glycogen-bound protein phosphatase G to modulator that was covalently bound to Sepharose. After elution from the column, the enzyme was identified as the free catalytic subunit (Mr 37,000).

Full text

PDF
659

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Alemany S., Pelech S., Brierley C. H., Cohen P. The protein phosphatases involved in cellular regulation. Evidence that dephosphorylation of glycogen phosphorylase and glycogen synthase in the glycogen and microsomal fractions of rat liver are catalysed by the same enzyme: protein phosphatase-1. Eur J Biochem. 1986 Apr 1;156(1):101–110. doi: 10.1111/j.1432-1033.1986.tb09554.x. [DOI] [PubMed] [Google Scholar]
  2. Doperé F., Stalmans W. Release and activation of phosphorylase phosphatase upon rupture of organelles from rat liver. Biochem Biophys Res Commun. 1982 Jan 29;104(2):443–450. doi: 10.1016/0006-291x(82)90657-x. [DOI] [PubMed] [Google Scholar]
  3. Doperé F., Vanstapel F., Stalmans W. Glycogen-synthase phosphatase activity in rat liver. Two protein components and their requirement for the activation of different types of substrate. Eur J Biochem. 1980 Feb;104(1):137–146. doi: 10.1111/j.1432-1033.1980.tb04409.x. [DOI] [PubMed] [Google Scholar]
  4. Foulkes J. G., Cohen P. The regulation of glycogen metabolism. Purification and properties of protein phosphatase inhibitor-2 from rabbit skeletal muscle. Eur J Biochem. 1980 Mar;105(1):195–203. doi: 10.1111/j.1432-1033.1980.tb04489.x. [DOI] [PubMed] [Google Scholar]
  5. Goris J., Waelkens E., Camps T., Merlevede W. Regulation of protein phosphatase activity by the deinhibitor protein. Adv Enzyme Regul. 1984;22:467–484. doi: 10.1016/0065-2571(84)90026-8. [DOI] [PubMed] [Google Scholar]
  6. Hemmings B. A., Resink T. J., Cohen P. Reconstitution of a Mg-ATP-dependent protein phosphatase and its activation through a phosphorylation mechanism. FEBS Lett. 1982 Dec 27;150(2):319–324. doi: 10.1016/0014-5793(82)80760-6. [DOI] [PubMed] [Google Scholar]
  7. Hiraga A., Cohen P. Phosphorylation of the glycogen-binding subunit of protein phosphatase-1G by cyclic-AMP-dependent protein kinase promotes translocation of the phosphatase from glycogen to cytosol in rabbit skeletal muscle. Eur J Biochem. 1986 Dec 15;161(3):763–769. doi: 10.1111/j.1432-1033.1986.tb10505.x. [DOI] [PubMed] [Google Scholar]
  8. Ingebritsen T. S., Cohen P. Protein phosphatases: properties and role in cellular regulation. Science. 1983 Jul 22;221(4608):331–338. doi: 10.1126/science.6306765. [DOI] [PubMed] [Google Scholar]
  9. Ingebritsen T. S., Stewart A. A., Cohen P. The protein phosphatases involved in cellular regulation. 6. Measurement of type-1 and type-2 protein phosphatases in extracts of mammalian tissues; an assessment of their physiological roles. Eur J Biochem. 1983 May 2;132(2):297–307. doi: 10.1111/j.1432-1033.1983.tb07362.x. [DOI] [PubMed] [Google Scholar]
  10. Mvumbi L., Doperé F., Stalmans W. The inhibitory effect of phosphorylase a on the activation of glycogen synthase depends on the type of synthase phosphatase. Biochem J. 1983 May 15;212(2):407–416. doi: 10.1042/bj2120407. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Mvumbi L., Stalmans W. High-affinity binding of glycogen-synthase phosphatase to glycogen particles in the liver. Role of glycogen in the inhibition of synthase phosphatase by phosphorylase a. Biochem J. 1987 Sep 1;246(2):367–374. doi: 10.1042/bj2460367. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Stalmans W., Bollen M., Mvumbi L. Control of glycogen synthesis in health and disease. Diabetes Metab Rev. 1987 Jan;3(1):127–161. doi: 10.1002/dmr.5610030107. [DOI] [PubMed] [Google Scholar]
  13. Strålfors P., Hiraga A., Cohen P. The protein phosphatases involved in cellular regulation. Purification and characterisation of the glycogen-bound form of protein phosphatase-1 from rabbit skeletal muscle. Eur J Biochem. 1985 Jun 3;149(2):295–303. doi: 10.1111/j.1432-1033.1985.tb08926.x. [DOI] [PubMed] [Google Scholar]
  14. Tung H. Y., Resink T. J., Hemmings B. A., Shenolikar S., Cohen P. The catalytic subunits of protein phosphatase-1 and protein phosphatase 2A are distinct gene products. Eur J Biochem. 1984 Feb 1;138(3):635–641. doi: 10.1111/j.1432-1033.1984.tb07962.x. [DOI] [PubMed] [Google Scholar]
  15. Vandenheede J. R., Goris J., Yang S. D., Camps T., Merlevede W. Conversion of active protein phosphatase to the ATP-Mg-dependent enzyme form by inhibitor-2. FEBS Lett. 1981 May 5;127(1):1–3. doi: 10.1016/0014-5793(81)80326-2. [DOI] [PubMed] [Google Scholar]
  16. Vandenheede J. R., Vanden Abeele C., Merlevede W. Isolation and characterization of two 70 kDa modulator-complexes from rabbit skeletal muscle. Biochem Biophys Res Commun. 1986 Mar 13;135(2):367–373. doi: 10.1016/0006-291x(86)90004-5. [DOI] [PubMed] [Google Scholar]
  17. Yang S. D., Vandenheede J. R., Merlevede W. A simplified procedure for the purification of the protein phosphatase modulator (inhibitor-2) from rabbit skeletal muscle. FEBS Lett. 1981 Sep 28;132(2):293–295. doi: 10.1016/0014-5793(81)81182-9. [DOI] [PubMed] [Google Scholar]

Articles from Biochemical Journal are provided here courtesy of The Biochemical Society

RESOURCES