Phosphorylation of calcineurin by glycogen synthase (casein) kinase-1

1987 ◽  
Vol 65 (10) ◽  
pp. 917-921 ◽  
Author(s):  
Toolsee J. Singh ◽  
Jerry H. Wang
Keyword(s):  
Gel Electrophoresis ◽  
Peptide Mapping ◽  
Glycogen Synthase ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Casein Kinase ◽  
Casein Kinase 1 ◽  
Calcineurin Activity ◽  
Potential Substrate

A previous study demonstrated that calcineurin preparations contain variable amounts of endogenous phosphate. This observation suggests that calcineurin may be regulated by protein phosphorylation. In this study we have used calcineurin as a potential substrate for eight different protein kinases and significant phosphorylation was observed only with glycogen synthase (casein) kinase-1 (CK-1). Analysis by sodium dodecyl sulfate – polyacrylamide gel electrophoresis revealed that only subunit A of calcineurin was phosphorylated. The incorporation of 32P into calcineurin catalyzed by CK-1 ranged from 0.4 to 1.5 mol, depending on the preparation of the substrate used. Peptide mapping revealed that two major sites on calcineurin were phosphorylated. No change in calcineurin activity was observed as a result of phosphorylation. The results of this study suggest that CK-1 may be responsible for phosphorylating calcineurin in vivo.

scholarly journals Degradation of myofibrillar proteins by trypsin-like serine proteinases.

1982 ◽  
Vol 201 (2) ◽  
pp. 279-285 ◽  
Author(s):  
J Kay ◽  
L M Siemankowski ◽  
R F Siemankowski ◽  
J A Greweling ◽  
D E Goll
Keyword(s):  
Skeletal Muscle ◽  
Gel Electrophoresis ◽  
Cysteine Proteinase ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Serine Proteinase ◽  
Myofibrillar Proteins ◽  
Serine Proteinases ◽  
Bovine Trypsin

The effects of the Ca2+-activated cysteine proteinase, the rat trypsin-like serine proteinase and bovine trypsin on myofibrillar proteins from rabbit skeletal muscle are compared. 2. Myofibrils that had been treated at neutral pH with the Ca2+-dependent proteinase and with the rat enzyme were (a) analyzed by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and (b) examined in the electron microscope. Treatment with each proteinase resulted in the loss of the Z-discs, but the rat enzyme caused much more extensive disruption of the ultrastructure and degraded more of the myofibrillar proteins. 3. Purified F-actin was almost totally resistant to the proteinases, whereas G-actin was degraded by the rat trypsin-like proteinase at a rate approx. 15 times faster than was obtained with bovine trypsin. 4. Similar results were obtained with alpha-actinin, whereas tropomyosin was degraded more readily by bovine trypsin than by the rat trypsin-like proteinase. 5. The implications of these findings for the non-lysosomal breakdown of myofibrillar proteins in vivo are considered.

Effects of sulphydryl reagents on the structure of dehistonized metaphase chromosomes

1985 ◽  
Vol 73 (1) ◽  
pp. 245-260
Author(s):  
P. Jeppesen ◽  
H. Morten
Keyword(s):  
Gel Electrophoresis ◽  
Heavy Metal Ions ◽  
Core Protein ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Cross Linking ◽  
Polypeptide Composition ◽  
Metaphase Chromosomes ◽  
Axial Structure

Dehistonized metaphase chromosomes lose their apparent axial organization (the ‘scaffold’) and sediment more slowly following exposure to beta-mercaptoethanol (BME). We have subsequently treated BME chromosomes with reagents that oxidize protein sulphydryls to disulphides, and found that if calcium is also present during the oxidation an apparently similar axial structure is restored following dehistonization, as seen by microscopic examination. In general, however, we do not find that oxidation restores the higher sedimentation rate of dehistonized control chromosomes. Analysis of residual core protein in dehistonized chromosomes by sodium dodecyl sulphate/polyacrylamide gel electrophoresis fails to detect any differences in polypeptide composition related to the state of oxidation or to the presence or absence of visible axial organization. Combining our results with those of other workers, we conclude that the axial structure evident in dehistonized metaphase chromosomes is maintained, at least partially, by inter-protein cross-linking, although in vivo this may not be via simple disulphide bridges. Additional factors, which we have not yet characterized, but which possibly include heavy metal ions, appear to be involved in the axial organization existing in vivo.

scholarly journals Dog and human acid β-d-galactosidases are structurally similar

1983 ◽  
Vol 213 (2) ◽  
pp. 473-478 ◽  
Author(s):  
J J Hubert ◽  
J S O′Brien
Keyword(s):  
Gel Electrophoresis ◽  
Human Liver ◽  
Peptide Mapping ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Major Band ◽  
Chymotryptic Peptide ◽  
Human Acid ◽  
Dog Liver ◽  
Peptide Maps

The purification of dog liver acid β-galactosidase is described. The dog enzyme migrated as a single major band on polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate, with a molecular weight of 60000. Antiserum raised against purified human liver acid β-galactosidase cross-reacted with β-galactosidase from dog liver, but not with those from cat liver or Escherichia coli. Tryptic peptide maps of the dog and human acid β-galactosidases indicate that 21 of the 24 peptides observed were homologous; a similar result was obtained after chymotryptic peptide mapping. We conclude that dog and human acid β-galactosidases are structurally similar, and that canine GM1 gangliosidosis (acid β-galactosidase deficiency) is an excellent model for the same disease in man.

Soluble High-Molecular-Weight E Fragments in the Plasmin-Induced Degradation Products of Cross-Linked Human Fibrin

1975 ◽  
Vol 49 (2) ◽  
pp. 149-156 ◽  
Author(s):  
P. J. Gaffney ◽  
D. A. Lane ◽  
M. Brasher
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Gel Electrophoresis ◽  
Factor Xiii ◽  
Degradation Products ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Cross Linking ◽  
D Dimer

1. The factor XIII-mediated cross-linked α chains in fibrin have no effect on the nature of the fragments released during the solubilization of fibrin by plasmin. 2. Besides the known D dimer and E fragments solubilized during the lysis of cross-linked fibrin, other fragments have been observed on sodium dodecyl sulphate-polyacrylamide gel electrophoresis which have a molecular weight of about 135 000. After prolonged plasmin digestion, these fragments (U fragments) were no longer evident on the gels and the high-molecular-weight E antigen was absent. It is assumed that the E antigen was associated with the U fragments. These fragments also cross-reacted with an anti-D serum. 3. The U fragments have been tentatively presumed to be a factor XIII-mediated cross-linked D–E complex since they degrade only after prolonged degradation with plasmin. Whereas it is known that the fibrin D dimer fragment contains the cross-linked γ chain residues of the originating fibrin, the presumed covalent cross-linking of the D–E fragments has not been proved. 4. The presence of these high-molecular-weight fragments, containing the E antigen, in cross-linked human fibrin digests should be taken into account in the development of D dimer assays to monitor fibrin lysis in vivo.

scholarly journals Characterization of an Escherichia coli O157:H7 Plasmid O157 Deletion Mutant and Its Survival and Persistence in Cattle

2007 ◽  
Vol 73 (7) ◽  
pp. 2037-2047 ◽  
Author(s):  
Ji Youn Lim ◽  
Haiqing Sheng ◽  
Keun Seok Seo ◽  
Yong Ho Park ◽  
Carolyn J. Hovde
Keyword(s):  
Escherichia Coli ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Differentially Expressed ◽  
Sequence Matching ◽  
Two Dimensional Gel Electrophoresis ◽  
E Coli ◽  
Cell Lysates

ABSTRACT Escherichia coli O157:H7 causes hemorrhagic colitis and hemolytic-uremic syndrome in humans, and its major reservoir is healthy cattle. An F-like 92-kb plasmid, pO157, is found in most E. coli O157:H7 clinical isolates, and pO157 shares sequence similarities with plasmids present in other enterohemorrhagic E. coli serotypes. We compared wild-type (WT) E. coli O157:H7 and an isogenic ΔpO157 mutant for (i) growth rates and antibiotic susceptibilities, (ii) survival in environments with various acidity, salt, or heat conditions, (iii) protein expression, and (iv) survival and persistence in cattle following oral challenge. Growth, metabolic reactions, and antibiotic resistance of the ΔpO157 mutant were indistinguishable from those of its complement and the WT. However, in cell competition assays, the WT was more abundant than the ΔpO157 mutant. The ΔpO157 mutant was more resistant to acidic synthetic bovine gastric fluid and bile than the WT. In vivo, the ΔpO157 mutant survived passage through the bovine gastrointestinal tract better than the WT but, interestingly, did not colonize the bovine rectoanal junction mucosa as well as the WT. Many proteins were differentially expressed between the ΔpO157 mutant and the WT. Proteins from whole-cell lysates and membrane fractions of cell lysates were separated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and two-dimensional gel electrophoresis. Ten differentially expressed ∼50-kDa proteins were identified by quadrupole-time of flight mass spectrometry and sequence matching with the peptide fragment database. Most of these proteins, including tryptophanase and glutamate decarboxylase isozymes, were related to survival under salvage conditions, and expression was increased by the deletion of pO157. This suggested that the genes on pO157 regulate some chromosomal genes.

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