Acetyl-CoA carboxylase kinases

Additional information <1> (<1> two other cAMP-independent kinases found, that phosphorylate but do not effect acetyl-CoA carboxylase kinase activity [6] <1> phosphorylation by cAMP-dependent protein kinase has the same effect on acetyl-CoA carboxylase activity then phosphorylation with acetyl-CoA carboxylase kinase-2 [6,7] <1> cAMP-dependent protein kinase identified, that phosphorylates and inactivates acetyl-CoA carboxylase in vitro, but appears not to be involved in regulation in vivo [8]) [6-8]... 

Munday, M.R. Hardie, D.G. Isolation of three cyclic-AMP-independent acetyl-CoA carboxylase kinases from lactating rat mammary gland and characterization of their effects on enzyme activity. Eur. J. Biochem., 141, 617-627 (1984)... 

Ottey, K.A. Takhar, S. Munday, M.R. Comparison of two cyclic-nucleotide-independent acetyl-CoA carboxylase kinase from lactating rat mammary gland identification of the kinase responsible for acetyl-CoA inactivation in vivo. Biochem. Soc. Trans., 17, 349-350 (1989)... 

Heesom, K.J. Moule, S.K. Denton, R.M. Purification of an insulin-stimulated acetyl-CoA carboxylase kinase from rat epididymal adipose tissue. Biochem. Soc. Trans., 23, 180S (1995)... 

Purification of Acetyl-CoA Carboxylase Kinase from Rat Liver"... 

Acetyl-CoA carboxylase kinase was purified as described in the text. The amount of... 

FIGURE 25.4 Models of the acetyl-CoA carboxylase polypeptide, with phosphorylation sites indicated, along with the protein kinases responsible. Phosphorylation at Ser " is primarily responsible for decreasing the affinity for citrate. 

Figure 21-6. Regulation of acetyl-CoA carboxylase by phosphorylation/dephosphorylation.The enzyme is inactivated by phosphorylation by AMP-activated protein kinase (AMPK), which in turn is phosphorylated and activated by AMP-activated protein kinase kinase (AMPKK). Glucagon (and epinephrine), after increasing cAMP, activate this latter enzyme via cAMP-dependent protein kinase. The kinase kinase enzyme is also believed to be activated by acyl-CoA. Insulin activates acetyl-CoA carboxylase, probably through an "activator" protein and an insulin-stimulated protein kinase.

Fig. 5 Proposed signal transduction mechanisms that stimulate the pheromone biosynthetic pathway in Helicoverpa zea and Bombyx mori. It is proposed that PBAN binds to a G protein-coupled receptor present in the cell membrane that upon PBAN binding will induce a receptor-activated calcium channel to open causing an influx of extracellular calcium. This calcium binds to calmodulin and in the case of B. mori will directly stimulate a phosphatase that will dephosphorylate and activate a reductase in the biosynthetic pathway. In H. zea the calcium-calmodulin will activate adenylate cyclase to produce cAMP that will then act through kinases and/or phosphatases to stimulate acetyl-CoA carboxylase in the biosynthetic pathway...

A protein kinase is an enzyme that phosphorylates many other proteins, changing their activity (e.g., phosphorylation of acetyl CoA carboxylase inhibits it). Examples of protein kinases ate listed in Table 1-9-2 along with the second messengers that activate them. 

Figure 7.15 Inhibition of acetyl-CoA carboxylase by cyclic AMP dependent protein kinase and AMP dependent protein kinase the dual effect of glucagon. Phosphorylation of acetyl-CoA carboxylase by either or both enzymes inactivates the enzyme which leads to a decrease in concentration of malonyl-CoA, and hence an increase in activity of carnitine palmitoyltransferase-I and hence an increase in fatty acid oxidation. Insulin decreases the cyclic AMP concentration maintaining an active carboxylase and a high level of malonyl-CoA to inhibit fatty acid oxidation.

Activation of a protein kinase that is responsible for many of the metabolic effects, for example increased activity of glycogen synthase, increased translocation of the glucose transporter molecules to the plasma membrane and increased activity of acetyl-CoA carboxylase. 

ACETATE KINASE ACETYL-CoA CARBOXYLASE ACETYL-CoA SYNTHETASE N-ACETYLCLUCOSAMINE KINASE ACTIN ATPase ACTOMYOSIN ATPase N-ACYLMANNOSAMINE KINASE ADENINE NUCLEOTIDE TRANSLOCASE ADENOSINE KINASE ADENYLATE KINASE (MYOKINASE) ADENYLYLSULFATE KINASE d-ALANINE-d-ALANINE LIGASE... 

Orthophosphate as substrate or product, ACETATE KINASE (PYROPHOSPHATE) ACETYL-CoA CARBOXYLASE ACID PHOSPHATASE ACTOMYOSIN ATPase ACYL PHOSPHATASE ASPARTATE-SEMIALDEHYDE DEHYDROGENASE ATPases... 

I-peptide kinase <1> (<1> highly specific for acetyl-CoA carboxylase, binds... 

Shiao, M.-S. Drong, R.F. Porter, J.W. The purification and properties of a protein kinase and the partial purification of a phosphoprotein phosphatase that inactivate and activate acetyl-CoA carboxylase. Biochem. Biophys. Res. Commun., 98, 80-87 (1981)... 

Lent, B.A. Kim, K.-H. Purification and properties of a kinase which phos-phorylates and inactivates acetyl-CoA carboxylase. J. Biol. Chem., 257, 1897-1901 (1982)... 

Vawas, D. Apazidis, A. Saha, A.K. Gamble, J. Patel, A. Kemp, B.E. Witters, L.A. Ruderman, N.B. Contraction-induced changes in acetyl-CoA carboxylase and 5 -AMP-activated kinase in skeletal muscle. J. Biol. Chem., 272, 13255-13261 (1997)... 

T Glycogen phosphorylase I Glycogen synthase I PFK-1 T FBPase-2 i Pyruvate kinase T PEP carboxykinase T Triacylglycerol lipase Perilipin phosphorylation T Acetyl-CoA carboxylase... 

Regulation of acetyl-CoA carboxylase by phosphorylation and dephosphorylation. Glucagon is known to activate cAMP-dependent protein kinase this kinase phosphorylates both serine 77 and serine 1200 of rat acetyl-CoA carboxylase, which inactivates the enzyme. However, there is also an AMP-dependent kinase that phosphorylates serine 79 and serine 1200 and inactivates the rat acetyl-CoA carboxylase. The relative importance of these two kinases in regulating the carboxylase in vivo is still unclear. Likewise, the phosphorylated enzyme is a substrate for several different protein phosphate phosphatases, and the physiologically relevant phosphatases are not known. Epinephrine may inhibit the carboxylase via a Ca2+-dependent protein kinase. 

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