Skip to main content
NCBI home page
Biochemical Journal logoLink to Biochemical Journal
. 1977 Oct 15;168(1):43–48. doi: 10.1042/bj1680043

Effect of lutropin on phosphorylation of endogenous proteins in testis Leydig cells. Correlation with testosterone production

Brian A Cooke 1, Monica L Lindh 1, Felix H A Janszen 1
PMCID: PMC1184115  PMID: 202256

Abstract

The effect of lutropin on phosphorylation of endogenous proteins in testis Leydig cells was investigated, by incubating purified Leydig cells with lutropin and [32P]Pi followed by sodium dodecyl sulphate/polyacrylamide-slab gel electrophoresis of the [32P]phosphoproteins. The radioactivity of the proteins was quantified by densitometry of the radio-autograms obtained. The following results were obtained. 1. Lutropin increased the amount of 32P incorporated into three proteins (A, B and C) with apparent mol.wts. of 14300, 57000 and 77600 respectively. 2. The increase in incorporation of 32P into these proteins was detectable within 5min, reaching a maximum in approx. 20min. 3. The 32P incorporated into protein B (but not proteins A and C) was significantly increased with 0.1 and 1.0ng of lutropin/ml. Incorporation of 32P into all three proteins was significantly increased with 10ng of lutropin/ml, reaching a maximum with 100ng/ml. 4. Testosterone production was significantly increased with 1ng of lutropin/ml, and between 10 and 1000ng/ml the degree of stimulation of testosterone production and incorporation of 32P into proteins A, B and C was similar. 5. Cyclic AMP production was significantly increased with 10ng of lutropin/ml and had not reached a maximum with 1000ng/ml. 6. In Leydig cells isolated from hypophysectomized rats 3h after injection of choriogonadotropin in vivo, phosphoproteins with the same molecular weights as proteins A, B and C were found. No further increases in incorporation of 32P into these proteins were obtained when lutropin was added to the Leydig cells in vitro. 7. Dibutyryl cyclic AMP (but not follitropin or testosterone) also stimulated the incorporation of 32P into proteins A, B and C in Leydig cells.

Full text

PDF
43

Images in this article

44Fig. 1.
on p.44

Selected References

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

  1. Catt K. J., Dufau M. L. Spare gonadotrophin receptors in rat testis. Nat New Biol. 1973 Aug 15;244(137):219–221. doi: 10.1038/newbio244219a0. [DOI] [PubMed] [Google Scholar]
  2. Cooke B. A., Lindh L. M., Janszen F. H. Role of cyclic AM in steroidogenesis in Leydig cells: discrepancies' between effects of luteinizing hormone and cholera toxin. FEBS Lett. 1977 Jan 15;73(1):67–71. [PubMed] [Google Scholar]
  3. Cooke B. A., Lindh M. L., Janszen F. H. Correlation of protein kinase activation and testosterone production after stimulation of Leydig cells with luteinizing hormone. Biochem J. 1976 Dec 15;160(3):439–446. doi: 10.1042/bj1600439. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Cooke B. A., van der Kemp A. J. Protein kinase activity in rat testis interstitial tissue. Effect of luteinizing hormone and other factors. Biochem J. 1976 Feb 15;154(2):371–378. doi: 10.1042/bj1540371. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Janszen F. H., Cooke B. A., van Driel M. J., van der Molen H. J. LH induction of a specific protein (LH-IP) in rat testis Leydig cells. FEBS Lett. 1976 Dec 1;71(2):269–272. doi: 10.1016/0014-5793(76)80948-9. [DOI] [PubMed] [Google Scholar]
  6. Janszen F. H., Cooke B. A., van Driel M. J., van der Molen H. J. Purification and characterization of Leydig cells from rat testes. J Endocrinol. 1976 Sep;70(3):345–359. doi: 10.1677/joe.0.0700345. [DOI] [PubMed] [Google Scholar]
  7. Janszen F. H., Cooke B. A., van der Molen H. J. Specific protein synthesis in isolated rat testis leydig cells. Influence of luteinizing hormone and cycloheximide. Biochem J. 1977 Feb 15;162(2):341–346. doi: 10.1042/bj1620341. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
  9. Mendelson C., Dufau M., Catt K. Gonadotropin binding and stimulation of cyclic adenosine 3':5'-monophosphate and testosterone production in isolated Leydig cells. J Biol Chem. 1975 Nov 25;250(22):8818–8823. [PubMed] [Google Scholar]
  10. Moyle W. R., Ramachandran J. Effect of LH on steroidogenesis and cyclic AMP accumulation in rat Leydig cell preparations and mouse tumor Leydig cells. Endocrinology. 1973 Jul;93(1):127–134. doi: 10.1210/endo-93-1-127. [DOI] [PubMed] [Google Scholar]
  11. Podesta E. J., Dufau M. L., Catt K. J. Adenosine 3',5'-monophosphate-dependent protein kinase of Leydig cells: in vitro activation and relationship to gonadotropin action upon cyclic AMP and steroidogenesis. FEBS Lett. 1976 Nov;70(1):212–216. doi: 10.1016/0014-5793(76)80760-0. [DOI] [PubMed] [Google Scholar]
  12. Podesta E. J., Dufau M. L., Catt K. J. Characterization of two forms of cyclic 3', 5'-adenosine monophosphate-dependent protein kinase in rat testicular interstitial cells. Mol Cell Endocrinol. 1976 Jun-Jul;5(1-2):109–122. doi: 10.1016/0303-7207(76)90074-5. [DOI] [PubMed] [Google Scholar]
  13. Rommerts F. F., Cooke B. A., Van der Kemp J. W., Van der Molen H. J. Effect of luteinizing hormone on 3',5'-cyclic AMP and testosterone production in isolated interstitial tissue of rat testis. FEBS Lett. 1973 Jun 15;33(1):114–118. doi: 10.1016/0014-5793(73)80172-3. [DOI] [PubMed] [Google Scholar]
  14. Rubin C. S., Rosen O. M. Protein phosphorylation. Annu Rev Biochem. 1975;44:831–887. doi: 10.1146/annurev.bi.44.070175.004151. [DOI] [PubMed] [Google Scholar]

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

RESOURCES