Phosphorylation of Sterol Carrier Protein 2 by Protein Kinase C

  • A. Steinschneider
  • M. P. McLean
  • J. T. Billheimer
  • H. C. Palfrey
  • G. Gibori


Ca++ has been implicated in the regulation of the steroidogenic response to tropic hormones (1–3), including the transport of cholesterol to the mitochondrial site of side-chain cleavage, a step thatmay also involve sterol carrier protein 2 (SCP2) (4). SCP2 is a cholesterol carrier that facilitates the intracellular transfer of cholesterol to cytochrome P450scc, the rate-limiting enzyme in the steroidogenic process, located in the inner mitochondrial membrane. Thus, changes in the content and/or activity of SCP2 may be expected to play a key role in cholesterol transport and, therefore, in steroidogenesis (5). SCP2 is present in nonsteroidogenic and steroidogenic tissues, including the ovary (6,7). Ovarian SCP2 closely resembles hepatic SCP2 in its amino acid composition (7) and, presumably, in its overall structure.


Granulosa Cell Myosin Light Chain Myosin Light Chain Kinase Luteal Cell Sterol Carrier 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Hall PF, Osawa S, Thomasson C. A role for calmodulin in the regulation of steroidogenesis. J Cell Biol 1981; 90:402–7.PubMedCrossRefGoogle Scholar
  2. 2.
    Carnegie JA, Tsang BK. The calcium-calmodulin system : participation in the regulation of steroidogenesis at different stages of granulosa cell differentiation. Biol Reprod 1984;30:515–22.PubMedCrossRefGoogle Scholar
  3. 3.
    Veldhuis JD, Klase JF, Demers LM, Chafouleas JG. Mechanisms subserving calcium’s modulation of luteinizing hormone action in isolated swine granulosa cells. Endocrinology 1984; 114:441–8.PubMedCrossRefGoogle Scholar
  4. 4.
    Vahouny GV, Chanderbhan R, Kharroubi A, Noland BJ, Pastuszyn A, Scallen TJ. Sterol carrier and lipid transfer proteins. Adv Lipid Res 1987; 22:83–113.PubMedGoogle Scholar
  5. 5.
    Trzeciak WH, Simpson ER, Scallen TJ, Vahouny GV, Waterman MR. Studies on the synthesis of sterol carrier protein-2 in rat adrenocortical cells in monolayer culture. J Biol Chem 1987; 262:3713–7.PubMedGoogle Scholar
  6. 6.
    Teerlink T, Van der Krift TP, Van Heusden PH, Wirtz KWA. Determination of nonspecific lipid transfer protein in rat tissues and Morris hepatomas by enzyme immunoassay. Biochim Biophys Acta 1984; 793:251–9.PubMedCrossRefGoogle Scholar
  7. 7.
    Tanaka T, Billheimer JT, Strauss JF III. Luteinized rat ovaries contain a sterol carrier protein. Endocrinology 1984; 114:533–40.PubMedCrossRefGoogle Scholar
  8. 8.
    Trzaskos JM, Gaylor JL. Cytosolic modulators of activities of microsomal enzymes of cholesterol biosynthesis; purification and characterization of a nonspecific lipid-trans-fer protein. Biochim Biophys Acta 1983; 751:52–65.PubMedCrossRefGoogle Scholar
  9. 9.
    Steinschneider A, Khan I. In vitro phosphorylation of midpregnant rat luteal proteins in the presence of polymyxin B and compound 48/80 [Abstract]. Endocrine Soc 70th Ann Meeting 1988; 343.Google Scholar
  10. 10.
    Wrenn RW, Wooten MW. Dual calcium dependent protein phosphorylation systems in pancreas and their differential regulation by polymyxin B. Life Sci 1984; 35:267–76.PubMedCrossRefGoogle Scholar
  11. 11.
    Pastuszyn A, Noland BJ, Bazan JF, Hetterick RJ, Scallen TH. Primary sequence and structural analysis of sterol carrier protein 2 from rat liver: homology with immunoglobulins. J Biol Chem 1987; 262:13219–27.PubMedGoogle Scholar
  12. 12.
    Shinohara O, Knecht M, Feng K, Catt KJ. Activation of protein kinase C potentiates cyclic AMP production and stimulates steroidogenesis in differentiated ovarian granulosa cells. J Steroid Biochem 1985; 24:161–8.Google Scholar
  13. 13.
    Kawai Y, Qark MR. Phorbol ester regulation of rat granulosa cell prostaglandin and progesterone accumulation. Endocrinology 1985; 116:2320–6.PubMedCrossRefGoogle Scholar
  14. 14.
    Brunswig B, Bohnet HG. Stimulation of progesterone production in bovine luteal cells by mezerin and the phorbol ester PMA. Acta Endocrinol [suppl] (Copenh) 1986; 111:72–3.Google Scholar
  15. 15.
    Gibson DM. Reversible phosphorylation of hepatic HMG-CoA reductase in endocrine and feedback control of cholesterol biosynthesis. In: Preiss B, ed. Regulation of HMG-CoA reductase. Academic Press, 1985:79–132.CrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1989

Authors and Affiliations

  • A. Steinschneider
    • 1
  • M. P. McLean
    • 1
  • J. T. Billheimer
    • 2
  • H. C. Palfrey
    • 3
  • G. Gibori
    • 1
  1. 1.Department of Physiology and Biophysics, College of MedicineUniversity of IllinoisChicagoUSA
  2. 2.DuPont Experimental StationWilmingtonUSA
  3. 3.University of ChicagoChicagoUSA

Personalised recommendations