Vaginal Fluid Adenosine 3',5'-Cyclic Monophosphate (cAMP) in the Rat: Interaction with Sperm cAMP-Dependent Protein Kinase Regulatory Subunits

Atherton, R. W.; Culver, Bruce; Seitz, Jürgen; Khatoon, Sabiha; Gern, William A.

doi:10.3109/01485018608986944

Cited by 7 publications

(2 citation statements)

References 26 publications

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“…These surface macromolecules may thus have a role in the regulation of sperm forward motility. The occurrence of cAMP in seminal plasma [48] and vaginal fluid [3] and of ATP in seminal plasma [14] and the finding that ATP may be translocated from the cytosol to the exterior of spermatozoa [go] are consistent with the above view because exogenous cAMP is required for the activation of ecto-kinase and ATP is needed for cell surface protein phosphorylation. The sperm ecto-phosphoproteins exhibit properties of regulatory proteins because they undergo rapid phosphorylation as well as turnover (Fig.…”

Section: 61supporting

confidence: 66%

Biochemical Parameters of Initiation and Regulation of Sperm Motility

Majumder

Dey

Haldar

et al. 1990

Archives of Andrology

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Studies of in vitro models demonstrate that a forward motility protein (FMP) is required for the initiation of forward motility in the immature epididymal spermatozoa. FMP is a heat-stable glycoprotein derived from epididymal plasma. During the epididymal maturation of spermatozoa in vivo, there is a marked increase of intrasperm pH and level of cyclic adenosine monophosphate (CAMP). Several studies suggest that exogenous FMP in concert with elevated intrasperm pH and level of cAMP initiates flagellar motility during the epididymal transit of sperm. cAMP activates sperm cytosolic CAMPdependent protein kinases, which in turn phosphorylate multiple intrasperm phosphoproteins that may regulate flagellar motility. Exogenous calcium ion activates intact sperm motility, although it inhibits motility of demembranated cells on reactivation. Occurrence of CAMP-dependent type I and II protein kinases, a novel CAMP-independent protein kinase, and a phosphoprotein phosphatase has been demonstrated on the external surface of spermatozoa. The sperm surface has a coupled-enzyme system: ecto-CAMP-independent protein kinase and phosphoprotein phosphatase that regulate the phosphorylation and dephosphorylation of endogenous sperm ectophosphoproteins. The specific activities of these ectoenzymes increase markedly during forward progression, suggesting that they may have a role in regulating flagellar motility.

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Section: 61supporting

confidence: 66%

Biochemical Parameters of Initiation and Regulation of Sperm Motility

Majumder

Dey

Haldar

et al. 1990

Archives of Andrology

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“…Protein kinases of the membrane elements could phosphorylate sperm surface proteins, sperm surface protein kinases may be modifed in activity to phosphorylate sperm proteins, or both possibilities could occur. For example, the cAMP-dependent protein kinase of the sperm surface (Schoff et al, 1982;Atherton et al, 1985) may be activated during ejaculation upon contact with cAMP in seminal vesicle secretion or vaginal fluid (Atherton et al, 1986). Sperm surface protein kinases can phosphorylate the sperm-binding proteins from seminal vesicle secretion (Wilson, 1987).…”

Section: Methodsmentioning

confidence: 99%

Membrane-associated protein kinase activities in seminal plasma from vasectomized men

Wilson

Kaye²,

Skalický³

et al. 1988

Reproduction

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Cauda epididymal sperm interactions with seminal vesicle fluid

Curry¹,

Atherton²

1992

Molecular Reproduction Devel

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The interaction of rat cauda epididymal sperm cAMP-dependent protein kinase (PKA) with seminal vesicle fluid (SVF) proteins was examined. Specific proteins in SVF act as substrates for the sperm cell PKA. The apparent molecular weights of these proteins are 45.0, 31.5, 17.2, 14.7, and 13.3 kDa. The phosphorylation of one low-molecular-weight cauda sperm protein is blocked in the presence of SVF. There is no PKA enzyme activity in SVF. The presence of phosphate transfer activity between the sperm cell enzyme and the SVF proteins is species dependent. For example, mouse and rat SVF proteins are efficient phosphate acceptors, but there is no phosphorylation activity when hamster SVF is used as the enzyme substrate. The sperm cell samples were also assessed for membrane integrity. Specifically, cauda sperm cells used in these assays were judged to be intact when examined microscopically using the fluorescent vital dye carboxyfluorodiacetate. Although there was enzyme activity in the supernatants of the rat sperm cell samples, in the protein kinase assay it required three times as much supernatant volume (compared with intact cell sample volume) to measure the activity. Supernatant enzyme activity did not increase with washing, indicating that the cells were not damaged by this procedure. The enzyme itself does not adhere to the sperm cells, so the PKA enzyme activity is most likely oriented on the external surface of the sperm cell.

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Vaginal Fluid Adenosine 3',5'-Cyclic Monophosphate (cAMP) in the Rat: Interaction with Sperm cAMP-Dependent Protein Kinase Regulatory Subunits

Cited by 7 publications

References 26 publications

Biochemical Parameters of Initiation and Regulation of Sperm Motility

Biochemical Parameters of Initiation and Regulation of Sperm Motility

Membrane-associated protein kinase activities in seminal plasma from vasectomized men

Cauda epididymal sperm interactions with seminal vesicle fluid

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