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Exogenous protein kinases A and C, but not endogenous prostasome-associated protein kinase, phosphorylate semenogelins I and II from human semen

Ek, P; Malm, Johan LU ; Lilja, Hans LU ; Carlsson, L and Ronquist, G (2002) In Journal of Andrology 23(6). p.806-814
Abstract
Semenogelins I and II are the quantitatively dominating proteins in human semen. They comprise the major part of the sperm-entrapping gel formed at ejaculation, which subsequently liquefies due to proteolysis of the gel-forming proteins by prostate-specific antigen (PSA). The mechanism behind gel formation and its physiological significance is not known. We have studied phosphorylation and dephosphorylation of human semenogelins. Both were phosphorylated by protein kinases A and C (PKA and PKC, respectively) at a rate about 5 times less than that of histone. For PKA, incorporated ( P)phosphate into semenogelin approached a maximum above 1 mol/mol. Corresponding values for phosphorylation of the semenogelins with PKC were greater than 10.... (More)
Semenogelins I and II are the quantitatively dominating proteins in human semen. They comprise the major part of the sperm-entrapping gel formed at ejaculation, which subsequently liquefies due to proteolysis of the gel-forming proteins by prostate-specific antigen (PSA). The mechanism behind gel formation and its physiological significance is not known. We have studied phosphorylation and dephosphorylation of human semenogelins. Both were phosphorylated by protein kinases A and C (PKA and PKC, respectively) at a rate about 5 times less than that of histone. For PKA, incorporated ( P)phosphate into semenogelin approached a maximum above 1 mol/mol. Corresponding values for phosphorylation of the semenogelins with PKC were greater than 10. There was no change in the sensitivity of phosphosemenogelins to proteolysis by PSA. Serine (PKA) and serine and threonine (PKC) were the phosphate-accepting amino acid residues, and all incorporated (P-32)phosphate could be removed from the semenogelins with human acid phosphatase. Nil or very little phosphate could be detected in purified semenogelins isolated from seminal plasma. In vivo, about half the protein kinase activity in seminal plasma was bound to prostasomes. PKA but not PKC purified from prostasomes could phosphorylate specific substrates, but they could phosphorylate either of the semenogelins. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
prostate-specific antigen, acid phosphatase, histone, vasectomy
in
Journal of Andrology
volume
23
issue
6
pages
806 - 814
publisher
American Society of Andrology
external identifiers
  • wos:000179179700013
  • scopus:0036868434
ISSN
0196-3635
language
English
LU publication?
yes
id
ea09e266-114f-452b-87b1-dfcca2bac13e (old id 324240)
alternative location
http://www.andrologyjournal.org/cgi/content/abstract/23/6/806
date added to LUP
2007-08-16 11:39:32
date last changed
2017-01-01 07:06:44
@article{ea09e266-114f-452b-87b1-dfcca2bac13e,
  abstract     = {Semenogelins I and II are the quantitatively dominating proteins in human semen. They comprise the major part of the sperm-entrapping gel formed at ejaculation, which subsequently liquefies due to proteolysis of the gel-forming proteins by prostate-specific antigen (PSA). The mechanism behind gel formation and its physiological significance is not known. We have studied phosphorylation and dephosphorylation of human semenogelins. Both were phosphorylated by protein kinases A and C (PKA and PKC, respectively) at a rate about 5 times less than that of histone. For PKA, incorporated ( P)phosphate into semenogelin approached a maximum above 1 mol/mol. Corresponding values for phosphorylation of the semenogelins with PKC were greater than 10. There was no change in the sensitivity of phosphosemenogelins to proteolysis by PSA. Serine (PKA) and serine and threonine (PKC) were the phosphate-accepting amino acid residues, and all incorporated (P-32)phosphate could be removed from the semenogelins with human acid phosphatase. Nil or very little phosphate could be detected in purified semenogelins isolated from seminal plasma. In vivo, about half the protein kinase activity in seminal plasma was bound to prostasomes. PKA but not PKC purified from prostasomes could phosphorylate specific substrates, but they could phosphorylate either of the semenogelins.},
  author       = {Ek, P and Malm, Johan and Lilja, Hans and Carlsson, L and Ronquist, G},
  issn         = {0196-3635},
  keyword      = {prostate-specific antigen,acid phosphatase,histone,vasectomy},
  language     = {eng},
  number       = {6},
  pages        = {806--814},
  publisher    = {American Society of Andrology},
  series       = {Journal of Andrology},
  title        = {Exogenous protein kinases A and C, but not endogenous prostasome-associated protein kinase, phosphorylate semenogelins I and II from human semen},
  volume       = {23},
  year         = {2002},
}