scholarly journals Akt1 and Akt2 Differently Regulate Muscle Creatine Kinase and Myogenin Gene Transcription in Insulin-Induced Differentiation of C2C12 Myoblasts

Endocrinology ◽  
2002 ◽  
Vol 143 (3) ◽  
pp. 820-828 ◽  
Author(s):  
Satoru Sumitani ◽  
Kayoko Goya ◽  
Joseph R. Testa ◽  
Haruhiko Kouhara ◽  
Soji Kasayama
1984 ◽  
Vol 259 (24) ◽  
pp. 15224-15227
Author(s):  
C P Ordahl ◽  
G L Evans ◽  
T A Cooper ◽  
G Kunz ◽  
J C Perriard

2020 ◽  
pp. 174751982097858
Author(s):  
M Vraneš ◽  
S Ostojić ◽  
Č Podlipnik ◽  
A Tot

Comparative molecular docking studies on creatine and guanidinoacetic acid, as well as their phosphorylated analogues, creatine phosphate, and phosphorylated guanidinoacetic acid, are investigated. Docking and density functional theory studies are carried out for muscle creatine kinase. The changes in the geometries of the ligands before and after binding to the enzyme are investigated to explain the better binding of guanidinoacetic acid and phosphorylated guanidinoacetic acid compared to creatine and creatine phosphate.


2006 ◽  
Vol 84 (2) ◽  
pp. 142-147
Author(s):  
Feng Shi ◽  
Tong-Jin Zhao ◽  
Hua-Wei He ◽  
Jie Li ◽  
Xian-Gang Zeng ◽  
...  

As a depressant of the central nervous system, the clinical effect of sodium barbital has been extensively studied. Here we report on sodium barbital as an inhibitor of rabbit-muscle creatine kinase (CK), which plays a significant role in energy homeostasis in the muscles. Although sodium barbital gradually inhibits the activity of CK with increased concentration, the inhibition effect can be completely reversed by dilution, indicating that the inactivation process is reversible. Detailed kinetics analysis, according to a previously presented theory, indicates that sodium barbital functions as a non complexing inhibitor, and its inhibition effect on CK is a slow reversible inactivation. In this study, a kinetic model of the substrate reaction is presented, and the microscopic rate constants for the reaction of sodium barbital with the free enzyme and the enzyme–substrate complexes are determined. Kinetic analysis reveals that sodium barbital might compete with both creatine and ATP, but mainly with creatine, to inhibit the activity of CK. The results suggest that CK might be a target for sodium barbital in vivo.Key words: creatine kinase; inactivation; kinetics; sodium barbital.


1990 ◽  
Vol 10 (9) ◽  
pp. 4826-4836 ◽  
Author(s):  
R A Horlick ◽  
G M Hobson ◽  
J H Patterson ◽  
M T Mitchell ◽  
P A Benfield

We have previously reported that the rat brain creatine kinase (ckb) gene promoter contains an AT-rich sequence that is a binding site for a protein called TARP (TA-rich recognition protein). This AT-rich segment is a positively acting regulatory element for the ckb promoter. A similar AT-rich DNA segment is found at the 3' end of the 5' muscle-specific enhancer of the rat muscle creatine kinase (ckm) gene and has been shown to be necessary for full muscle-specific enhancer activity. In this report, we show that TARP binds not only to the ckb promoter but also to the AT-rich segment at the 3' end of the muscle-specific ckm enhancer. A second, weaker TARP-binding site was identified in the ckm enhancer and lies at the 5' end of the minimal enhancer segment. TARP was found in both muscle cells (C2 and L6 myotubes) and nonmuscle (HeLa) cells and appeared to be indistinguishable from both sources, as judged by gel retardation and footprinting assays. The TARP-binding sites in the ckm enhancer and the ckb promoter were found to be functionally interchangeable. We propose that TARP is active in both muscle and nonmuscle cells and that it is one of many potential activators that may interact with muscle-specific regulators to determine the myogenic phenotype.


2000 ◽  
Vol 2 (1) ◽  
pp. 16-25 ◽  
Author(s):  
Michael A. Hauser ◽  
Ann Robinson ◽  
Dennis Hartigan-O'Connor ◽  
DeeAnn Williams-Gregory ◽  
Jean N. Buskin ◽  
...  

1988 ◽  
Vol 8 (1) ◽  
pp. 62-70
Author(s):  
J B Jaynes ◽  
J E Johnson ◽  
J N Buskin ◽  
C L Gartside ◽  
S D Hauschka

Muscle creatine kinase (MCK) is induced to high levels during skeletal muscle differentiation. We have examined the upstream regulatory elements of the mouse MCK gene which specify its activation during myogenesis in culture. Fusion genes containing up to 3,300 nucleotides (nt) of MCK 5' flanking DNA in various positions and orientations relative to the bacterial chloramphenicol acetyltransferase (CAT) structural gene were transfected into cultured cells. Transient expression of CAT was compared between proliferating and differentiated MM14 mouse myoblasts and with nonmyogenic mouse L cells. The major effector of high-level expression was found to have the properties of a transcriptional enhancer. This element, located between 1,050 and 1,256 nt upstream of the transcription start site, was also found to have a major influence on the tissue and differentiation specificity of MCK expression; it activated either the MCK promoter or heterologous promoters only in differentiated muscle cells. Comparisons of viral and cellular enhancer sequences with the MCK enhancer revealed some similarities to essential regions of the simian virus 40 enhancer as well as to a region of the immunoglobulin heavy-chain enhancer, which has been implicated in tissue-specific protein binding. Even in the absence of the enhancer, low-level expression from a 776-nt MCK promoter retained differentiation specificity. In addition to positive regulatory elements, our data provide some evidence for negative regulatory elements with activity in myoblasts. These may contribute to the cell type and differentiation specificity of MCK expression.


1989 ◽  
Vol 9 (2) ◽  
pp. 594-601
Author(s):  
E A Sternberg ◽  
G Spizz ◽  
M E Perry ◽  
E N Olson

Differentiation of skeletal myoblasts is accompanied by induction of a series of tissue-specific genes whose products are required for the specialized functions of the mature muscle fiber. The program for myogenic differentiation is subject to negative control by several peptide growth factors and by the products of mutationally activated ras oncogenes, which persistently activate intracellular cascades normally triggered by specific growth factors. Previously, we reported that induction of the muscle creatine kinase (mck) gene during myogenesis was dependent on a distal upstream enhancer that cooperated with a proximal promoter to direct high levels of expression in developing muscle cells (E. A. Sternberg, G. Spizz, W. M. Perry, D. Vizard, T. Weil, and E. N. Olson, Mol. Cell. Biol. 8:2896-2909). To investigate the mechanisms whereby ras blocks the induction of muscle-specific genes, we have examined the ability of mck 5' regulatory elements to direct expression of the linked reporter gene for chloramphenicol acetyltransferase (cat) in C2 myoblasts bearing mutant N-ras and H-ras oncogenes. In this paper we report that expression of activated ras alleles abolishes activity of the mck upstream enhancer but does not affect the activity of the mck promoter. The ability of ras to repress the expression of mck-cat fusion genes that have been transfected either transiently or stably into myoblasts suggests that ras may exert its effects on muscle-specific genes through mechanisms independent of chromatin configurations or DNA methylation. These results also suggest that ras blocks establishment of the myogenic phenotype by preventing the accumulation of regulatory factors required for transcriptional induction of muscle-specific genes.


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