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Full-Text Articles in Molecular Biology
Discovering The Sequence Specificity Of Human Dyrk2 And Dyrk4, Julie Klaric
Discovering The Sequence Specificity Of Human Dyrk2 And Dyrk4, Julie Klaric
University Scholar Projects
Protein phosphorylation is a post-translational modification (PTM) that is ubiquitous in regulating cellular processes. It is the most common PTM used in signal translation. Protein kinases are the class of enzymes that catalyze the transfer of a phosphate group from ATP to a specific amino acid on a substrate protein. In eukaryotes, kinases generally add a phosphate to serine, threonine, or tyrosine residues. Short linear patterns in the amino acid sequence of the substrate protein help guide the protein kinase to the correct residue to be phosphorylated. However, these patterns, or “motifs,” as well as the complete list of substrates …
The Cγ Subunit Is A Unique Isozyme Of The Camp-Dependent Protein Kinase, Stephen J. Beebe, Paul Salomonsky, Tore Jahnsen, Yixin Li
The Cγ Subunit Is A Unique Isozyme Of The Camp-Dependent Protein Kinase, Stephen J. Beebe, Paul Salomonsky, Tore Jahnsen, Yixin Li
Bioelectrics Publications
There are at least three isozymes (Cα, Cβ, and Cγ) of the mammalian catalytic (C) subunit of cAMP-dependent protein kinase (PKA) (Beebe, S., Oyen, O., Sandberg, M., Froysa, A., Hansson, V., and Jahnsen, T. (1990) Mol. Endocrinol. 4, 465-475). To compare the Cγ and Cα isozymes, the respective cDNAs were expressed in permanently transformed Kin-8 PKA-deficient Y1 adrenal cells using the mouse metallothionein promoter. The recombinant C subunits were characterized as immunoreactive, zinc-inducible, cAMP-dependent kinase activities. In contrast to Cα, histone was a better substrate than Leu-Arg-Arg-Ala-Ser-Leu-Gly (Kemptide) for Cγ. Furthermore, Cγ histone kinase activity was not inhibited by the …
Camp-Dependent Protein Kinase Activation Lowers Hepatocyte Camp, Jackie D. Corbin, Stephen J. Beebe, Peter F. Blackmore
Camp-Dependent Protein Kinase Activation Lowers Hepatocyte Camp, Jackie D. Corbin, Stephen J. Beebe, Peter F. Blackmore
Bioelectrics Publications
Rat hepatocyte protein kinase was activated by incubating the cells with various cAMP analogs. Boiled extracts were then prepared and Sephadex G-25 chromatography was carried out. The G-25 procedure separated the analogs from cAMP since the resin had the unexpected property of binding cyclic nucleotides with differing affinities. Separation was necessary because the analogs would otherwise interfere with the sensitive protein kinase activation method developed for assay of cAMP. The cAMP analogs, but not 5'-AMP, lowered basal cAMP by 50-70%. The effect was rapid, analog concentration-dependent, and occurred parallel with phosphorylase activation, suggesting that the cAMP analogs act through cAMP-dependent …
Purification And Characterization Of A Camp- And Ca2+-Calmodulin-Independent Glycogen Synthase Kinase From Porcine Renal Cortex, Stephen J. Beebe, Erwin M. Reimann, Keith K. Schlender
Purification And Characterization Of A Camp- And Ca2+-Calmodulin-Independent Glycogen Synthase Kinase From Porcine Renal Cortex, Stephen J. Beebe, Erwin M. Reimann, Keith K. Schlender
Bioelectrics Publications
We recently reported the partial purification of a cAMP-independent and Ca2+-calmodulin-independent glycogen synthase kinase from porcine renal cortex (Schlender, K. K., Beebe, S. J., and Reimann, E. M. (1981) Cold Spring Harbor Conf. Cell Proliferation, 389-400). Subsequent purification indicated that the enzyme preparation consisted of at least three forms of glycogen synthase kinase which could be resolved by ATP gradient elution from aminoethylphosphate-agarose (AEP-agarose). The predominant form of glycogen synthase kinase, which eluted from AEP-agarose between 2 and 6 mM ATP, was purified approximately 800-fold and is designated GSK-A1. It had a molecular weight of 45,000-50,000 as determined …
Microheterogeneity Of Type Ii Camp-Dependent Protein Kinase In Various Mammalian Species And Tissues, Alison M. Robinson-Steiner, Stephen J. Beebe, Stephen R. Rannels, Jackie D. Corbin
Microheterogeneity Of Type Ii Camp-Dependent Protein Kinase In Various Mammalian Species And Tissues, Alison M. Robinson-Steiner, Stephen J. Beebe, Stephen R. Rannels, Jackie D. Corbin
Bioelectrics Publications
Excluding autophosphorylated species, at least six forms of the regulatory subunit of type II cAMP-dependent protein kinase (R(II)) from various mammalian tissues were identified by sodium dodecyl sulfate (SDS) gel electrophoresis of purified samples and of crude preparations photoaffinity labeled with 8-azido[32P] cAMP and by gel filtration. After autophosphorylation some heart R(II) forms termed type IIA (bovine, porcine, equine, and dog) shifted to a more slowly migrating band on SDS gels while others termed type IIB (rat, guinea pig, rabbit, and monkey) did not detectably shift. Both subclasses of R(II) exhibited variation in apparent M(r) on SDS gels. Bovine and …
Two Classes Of Camp Analogs Which Are Selective For The Two Different Camp-Binding Sites Of Type Ii Protein Kinase Demonstrate Synergism When Added Together To Intact Adipocytes, Stephen J. Beebe, Rob Holloway, Stephen R. Rannels, Jackie D. Corbin
Two Classes Of Camp Analogs Which Are Selective For The Two Different Camp-Binding Sites Of Type Ii Protein Kinase Demonstrate Synergism When Added Together To Intact Adipocytes, Stephen J. Beebe, Rob Holloway, Stephen R. Rannels, Jackie D. Corbin
Bioelectrics Publications
Twenty-five cyclic nucleotide analogs were tested individually to act as lipolytic agents and to activate adipocyte protein kinase. The lipolytic potency of individual analogs correlated better with their K(a) for protein kinase and their lipophilicity rather than with either parameters alone. Some of the most potent lipolytic analogs had high I50 values for the particulate low K(m) cAMP phosphodiesterase suggesting that their effect was not due to raising endogenous cAMP levels through inhibition of phosphodiesterase. The most potent lipolytic analogs contained a thio moiety at the C-8 or C-6 position. These analogs exhibited concave upward dose-response curves. At high concentrations …