Type I and II cAMP-dependent ecto-protein kinases in goat epididymal spermatozoa and their enriched activities in forward-motile spermatozoa

1990 ◽  
Vol 68 (2) ◽  
pp. 459-470 ◽  
Author(s):  
Chinmoy S. Dey ◽  
Gopal C. Majumder

Several lines of evidence have demonstrated conclusively the presence of cAMP-dependent protein kinase (ecto-RC) activity on the external surface of goat cauda-epididymal intact spermatozoa. The intact-cell ecto-kinase that caused transfer of the terminal phosphate of exogenous ATP to the serine and threonine residues of exogenous histone was specifically activated by cAMP. As well, the ecto-kinase caused phosphorylation of the synthetic peptide Kemptide. The isolated spermatozoa, before or after incubation with reaction mixture for ecto-kinase assays, were ~ 99.5% viable, as shown by the analyses of ethidium bromide fluorescence and the cytosolic marker enzymes lactic dehydrogenase and 3-phosphoglycerate kinase. The ecto-kinase activity was not due to contamination of epididymal plasma and damaged cells or to protein kinase that may have leaked from the cells. There was little uptake of ATP and histone by the cells. The intact-cell kinase activity was strongly (80–90%) inhibited by treatment with membrane nonpenetrating surface probes: p-chloromercuriphenylsulfonic acid (2 μM), diazonium salt of sulfanilic acid (DSS, 0.5 mM), and proteases such as trypsin, chymotrypsin, and pronase (each 125 μg/mL). Disruption of sperm plasma membrane by sonication or Triton X-100 (0.2%) caused about a fivefold increase of the intact sperm kinase activity. Highly purified sperm plasma membrane (PM) possessed ecto-kinase activity that was resolved into type I and II kinases by DEAE-cellulose chromatography, the type I isoenzyme being the major (~ 70%) enzymic species. Treatment of the intact spermatozoa with DSS prior to isolation of PM caused a marked loss of the activities of both the isoenzymes, indicating thereby the "ecto" nature of the PM-bound type I and II kinases. Preparations of vigorously forward-motile spermatozoa with 100% intactness had approximately fourfold higher specific activity of the ecto-kinase than the "composite" cells from which the former cells were isolated. However, the profiles of the type I and II ecto-kinases of the composite, as well as forward-motile spermatozoa, were nearly identical. The data are consistent with the view that ecto-kinases may have role in the regulation of flagellar motility.Key words: spermatozoa, ecto-protein kinases, cAMP, plasma membrane, cell intactness.

1994 ◽  
Vol 72 (5-6) ◽  
pp. 218-226 ◽  
Author(s):  
Sutapa Mitra ◽  
Debjani Nath ◽  
Gopal C. Majumder

A protein kinase that causes phosphorylation of serine and threonine residues of casein has been partially purified from goat cauda-epididymal sperm plasma membrane and characterized. The kinase, solubilized from the membrane with 1.0% Triton X-100, was purified to 480-fold by using DEAE-cellulose and casein-Sepharose affinity chromatographic techniques. The kinase is a strongly basic protein with pI of 9.5. The enzyme has a molecular mass of 310 kilodaltons as estimated by Sephacryl S-300 gel exclusion. The kinase showed affinity for protein substrates in the order membrane proteins > casein > phosvitin > histone > protamine. The apparent Km values of the kinase for casein and membrane proteins were 1 and 0.15 mg/mL, respectively. The synthetic peptides Kemptide and poly(Glu80Tyr20) did not serve as substrates of the enzyme. ATP, rather than GTP or PP, is the donor of phosphate for the phosphorylation reaction. Cyclic AMP and GMP, NaCl (0.25 M), KCl (0.25 M), Ca2+, calmodulin, phosphatidylserine, and muscle protein kinase inhibitor had no appreciable effect on the kinase activity. Heparin (0.5 μg/mL) showed high affinity for inhibiting only 40% of the kinase activity, whereas polyamines at a relatively high concentration (5 mM) inhibited 40–50% of the enzymic activity. The kinase appears to be distinct from other protein kinases including casein kinases. The activity of the kinase derived from the purified sperm plasma membrane was markedly (~ 90%) lost when the intact spermatozoa were pretreated with diazonium salt of sulfanilic acid, a membrane nonpenetrating surface probe. The data are consistent with the view that the isolated enzyme is an ecto-protein kinase whose catalytic site is oriented primarily to the surface of viable sperm cell to cause phosphorylation of the endogenous outer cell-surface phosphoproteins.Key words: spermatozoa, plasma membrane, protein kinase, phosphoproteins, ectoenzyme.


1975 ◽  
Vol 53 (2) ◽  
pp. 207-214 ◽  
Author(s):  
Elena A. Bernard ◽  
G. F. Wassermann

Protein kinase activity of rat testis homogenate was separated into five fractions by means of pH 4.8 acidification and DEAE-cellulose chromatography. The five fractions showed a peculiar pattern of activity and cAMP dependency with the substrates used: casein, protamine, histone mixture, arginine-rich histone, lysine-rich histone, and phosvitin. The casein–sepharose substrate affinity column separated two fractions from the pH 4.8 precipitate. Peak number one phosphorylates histone preferently and is cAMP-dependent, while peak number two has a strong affinity toward casein as substrate and is not cAMP-dependent.


1981 ◽  
Vol 36 (7-8) ◽  
pp. 552-561 ◽  
Author(s):  
W. Pyerin ◽  
N. Baibach ◽  
D. Kübler ◽  
V. Kinzel

Abstract Extracts of HeLa cell fractions were analyzed by DEAE-and phospho-cellulose chromatog­ raphy for their range of cyclic AMP-dependent and -independent protein kinase activities phosphorylating histone and/or phosvitin; extractions were by phosphate buffered saline (soluble protein kinases) and the non-ionic detergent NP-40 (membrane-bound protein kinases). The soluble fraction contained (i) cyclic AMP-dependent histone kinases type I and II as evidenced by their behaviour on DEAE-cellulose and inhibition by the specific heat-and acid-stable protein kinase inhibitor (PKI) in a dose-related manner; both types I and II as well as their purified catalytic subunit also phosphorylated protamine and — with very low efficiency -casein but not phosvitin; (ii) a histone kinase (H), insensitive to cyclic AMP and PKI, also accepting protamine as substrate but not either casein or phosvitin; (iii) a phosvitin kinase (P), insensitive to cyclic AMP and PKI, which also phosphorylates casein but not histone or protamine. These four enzyme species were also found in NP-40 extracts of 27000x g residues which, however, contained further histone and phosvitin kinase activities as yet unspecified. NP-40 extracts of the microsomal fraction possessed, besides unspecified histone and phosvitin kinase activity, only the phosvitin kinase P and appeared to be devoid of histone kinases I, II, and H. The occurrence and ratios of the protein kinases classified suggest an ordered distribution over the diverse subcellular fractions of HeLa cells. The overall pattern of soluble and membrane-bound histone and phosvitin kinases in extracts of cervix carcinoma tissue, the in vivo correlate of HeLa cells, closely resembled that of similar extracts of HeLa cells. HeLa cells hence appear, despite their long in vitro history, to express protein kinase activities similar to those of their in vivo ancestors, recommending them as a subject for the study of (certain) human protein kinase systems.


1978 ◽  
Vol 170 (3) ◽  
pp. 469-477 ◽  
Author(s):  
G Schwoch

The protein-bound cyclic AMP and the activity of cytosolic protein kinases in the presence and absence of cyclic AMP were determined in rat liver up to 2h after injection of glucagon. On the basis of the different salt-sensitivities of the activated cyclic AMP-dependent proteinkinases I and II, an activation of protein kinase II restricted to the high cyclic AMP concentrations present in the first 30 min after hormone injection was found. Essentially the same result was obtained by chromatographic analysis on DEAE-cellulose of liver cytosol from untreated rats and from rats killed at 2 and 60 min after glucagon injection. Protein kinase II activation was only detected at 2 min after injection. In contrast, the cyclic AMP-dependent protein kinase I was found to be nearly totally activated at 2 min and to be still almost as active at 60 min after the hormone stimulus, whereas the amount of bound cyclic AMP and the activation of total cytosolic protein kinases had fallen to two-thirds of their maximal values during this time period. A third cyclic AMP-independent protein kinase, which co-chromatographed with protein kinase type II, could be clearly distinguished from the two cyclic AMP-dependent kinases by use of the heat-stable inhibitor from bovine muscle, which totally inhibited the cyclic AMP-dependent enzymes, but stimulated the cyclic AMP-independent protein kinase.


1981 ◽  
Vol 9 (2) ◽  
pp. 232P-232P
Author(s):  
G. J. Belsham ◽  
R. W. Brownsey ◽  
R. M. Denton

1991 ◽  
Vol 11 (8) ◽  
pp. 4045-4052 ◽  
Author(s):  
S Garrett ◽  
M M Menold ◽  
J R Broach

Null mutations in the gene YAK1, which encodes a protein with sequence homology to known protein kinases, suppress the cell cycle arrest phenotype of mutants lacking the cyclic AMP-dependent protein kinase (A kinase). That is, loss of the YAK1 protein specifically compensates for loss of the A kinase. Here, we show that the protein encoded by YAK1 has protein kinase activity. Yak1 kinase activity is low during exponential growth but is induced at least 50-fold by arrest of cells prior to the completion of S phase. Induction is not observed by arrest at stages later in the cell cycle. Depending on the arrest regimen, induction can occur either by an increase in Yak1 protein levels or by an increase in Yak1 specific activity. Finally, an increase in Yak1 protein levels causes growth arrest of cells with attenuated A kinase activity. These results suggest that Yak1 acts in a pathway parallel to that of the A kinase to negatively regulate cell proliferation.


1978 ◽  
Vol 175 (2) ◽  
pp. 367-375 ◽  
Author(s):  
A M Malkinson ◽  
A J Gharrett ◽  
L Hogy

1. DEAE-cellulose chromatography of mouse brain cytosol indicated the presence of only the type II isoenzyme of cyclic AMP-dependent protein kinase. Mouse heart cytosol contained approximately equal amounts of the type I and type II isoenzymes. 2. Both brain and heart type II isoenzymes reassociated after a transient exposure to cyclic AMP, but the heart type I isoenzyme remained dissociated. 3. Elution of brain cytosol continuously exposed to cyclic AMP resolved multiple peaks of protein kinase and cyclic AMP-binding activities. A single peak of kinase and multiple peaks of cyclic AMP-binding activities were found under the same conditions with heart cytosol. Various control experiments suggested that the heterogeneity within the brain type II isoenzymic class had not been caused by proteolysis. 4. Kinetic experiments with unfractionated brain cytosol showed that the binding of cyclic AMP, the dissociation of cyclic AMP from protein and the rate of heat denaturation of the cyclic AMP-binding activity gave results consistent with the presence of multiple binding species. 5. It concluded that the type II isoenzymic peak obtained by DEAE-cellulose chromatography of mouse brain cytosol represents a class of enzymes containing multiple regulatory and catalytic subunits. The two heart cytosol isoenzymes contain a common catalytic subunit. The degree of protein kinase ‘microheterogeneity”, defined as the presence of multiple regulatory and/or catalytic subunits within a single isoenzymic class, appears to be tissue-specific.


1994 ◽  
Vol 5 (3) ◽  
pp. 273-282 ◽  
Author(s):  
S Kornbluth ◽  
B Sebastian ◽  
T Hunter ◽  
J Newport

The key regulator of entry into mitosis is the serine/threonine kinase p34cdc2. This kinase is regulated both by association with cyclins and by phosphorylation at several sites. Phosphorylation at Tyr 15 and Thr 14 are believed to inhibit the kinase activity of cdc2. In Schizosaccharomyces pombe, the wee1 (and possibly mik1) protein kinase catalyzes phosphorylation of Tyr 15. It is not clear whether these or other, as yet unidentified, protein kinases phosphorylate Thr 14. In this report we show, using extracts of Xenopus eggs, that the Thr 14-directed kinase is tightly membrane associated. Specifically, we have shown that a purified membrane fraction, in the absence of cytoplasm, can promote phosphorylation of cdc2 on both Thr 14 and Tyr 15. In contrast, the cytoplasm can phosphorylate cdc2 only on Tyr 15, suggesting the existence of at least two distinctly localized subpopulations of cdc2 Tyr 15-directed kinases. The membrane-associated Tyr 15 and Thr 14 kinase activities behaved similarly during salt or detergent extraction and were similarly regulated during the cell cycle and by the checkpoint machinery that delays mitosis while DNA is being replicated. This suggests the possibility that a dual-specificity membrane-associated protein kinase may catalyze phosphorylation of both Tyr 15 and Thr 14.


2020 ◽  
Vol 46 (Supplement_1) ◽  
pp. S107-S108
Author(s):  
Robert McCullumsmith ◽  
Khaled Alganem ◽  
Nicholas Henkel ◽  
Abdul Hammoud ◽  
Rammohan Shukla ◽  
...  

Abstract Background Abnormalities of cellular signaling are well characterized in neuropsychiatric illnesses, including schizophrenia. Changes in signaling pathways reflect the underlying genetic, environmental, and epigenetic perturbations driving disease phenotypes. A shortcoming of most signaling studies is a focus on one or a few protein kinases at a time, a limitation since protein kinases work in networks with other kinases, phosphatases, and regulatory molecules to effect signaling events. We addressed this challenge by employing a kinome array platform that simultaneously measures protein kinase activity at hundreds of reporter peptide substrates. We then developed a novel bioinformatics pipeline to identify protein kinase nodes, signaling networks, upstream biological pathways, and drug candidates that “reverse” kinomic disease signatures. Methods Postmortem DLPFC brain samples from subjects with schizophrenia (n = 20 per group, 10 males and 10 females per group), were compared to age, PMI and pH matched control subjects (n = 20 per group, 10 males and 10 females per group) using the Pamgene12 serine/threonine kinome array chip. Samples were pooled by diagnosis and gender, and run in triplicate. The R-shiny app KRSA was created to automate assignment of kinases, perform permutation analyses, identify biological pathways, and connect to iLINCs for identification of drugs that reverse kinomic disease signatures. We also performed targeted confirmation studies using specific kinase activity assays, QPCR, and western blot analyses. Results We identified unique and common kinase nodes for each diagnostic group. Several of the nodes (for example AKT) are well characterized in schizophrenia, while others have not previously been identified (such as AMPK). We used AMPK KD cultures and AMPK KO brain tissues to demonstrate the validity if the kinome array for this protein kinase. We used standard kinase activity assays for AMPK and found decreased activity for AMPK (P < 0.05). We also found decreased expression of transcripts for the regulatory subunits of AMPK (P < 0.05). We identified several unique biological pathways, as well as candidate drugs, associated with the disease signature in schizophrenia. Discussion Our results confirm well characterized signaling defects in severe neuropsychiatric illness, and identify novel signaling nodes for further study. Confirmation studies for AMPK kinase show significant changes in expression and activity of this kinase, suggesting perturbation of energy sensing and production pathways in schizophrenia. Bioenergetic pathways may be targeted by myriad mechanisms, and we identified several drug candidates that might help restore this pathway in afflicted persons. Overall our novel workflow and pipeline provides a promising new avenue for understanding the complex signaling perturbations found in brain diseases and may provide new leads for developing treatments for schizophrenia and other cognitive disorders.


Sign in / Sign up

Export Citation Format

Share Document