Kinase-catalyzed phosphorylation

Adenosine kinase catalyzes phosphorylation of adenosine and deoxyadenosine to AMP and dAMP, and de-oxycytidine kinase phosphorylates deoxycytidine and 2 -deoxyguanosine to dCMP and dGMP. 

Fig. 15.9. Antiapoptotic signalling by the PI3-kinase/Akt kinase pathway The PI3 kinase/Akt kinase pathway influences apoptosis via phosphorylation of the Bad protein, which is a member of the family of Bcl-2 proteins. Activation of the PI3-kinase pathway leads to Akt-kinase-catalyzed phosphorylation of Bad protein. Bad protein in its unphosphorylated form participates in activation of initiator caspases and thus has a proapoptotic effect. Phosphorylation of Bad protein by Akt kinase (or related kinases) has an antiapoptotic effect since phosphoryla-ted Bad protein is a binding substrate of 14-3-3 proteins. Bad is thus sequestered in an inactive state and is not available for triggering of apoptosis.

Itoh, T., Kaibuchi, K., Sasaki, T., and Takai, Y. (1991). The smg GDS-induced activation of smg p21 is initiated by cyclic AMP-dependent protein kinase-catalyzed phosphorylation of smg p21. Biochem Biophys Res Commun 177 1319—1324. 

Figure 8 Kinase-catalyzed phosphorylation and phosphatases-catalyzed dephosphorylation reactions, (a) Catalytic mechanism of protein kinases (b) Catalytic mechanism of bimetallic pSer/pThr or dual specifity protein phosphatases (c) Catalytic mechanism of pTyr phosphatases.

Nucleoside Monophosphate Kinases Catalyzing Phosphoryl Group Exchange between Nucleotides Without Promoting Hydrolysis... 

The kinase-catalyzed phosphorylation of itself or an identical molecule is called. ... 

Usui H, Inoue R, Tanabe O et al (1998) Activation of protein phosphatase 2A by cAMP-dependent protein kinase-catalyzed phosphorylation of the 74-kDa B 5 regulatory subimit in vitro and identification of the phosphorylation sites. FEBS Lett 430 312-316... 

These schemes have now been used to prepare organic materials on scales of several moles. An example relevant to asymmetric synthesis is the glycerol kinase-catalyzed phosphorylation of glycerol (equation i) (6). 

Isoenzymes (or isozymes) are multiple forms of an enzyme that differ from each other in such properties as substrate affinity, maximum activity, or regulatory properties. They may be found in different tissues or portions of the same cell. For example, thymidine kinase catalyzing phosphorylation occurs as two isoenzymes—one in the cytoplasm and the other associated with the mitochondria of the same mammalian cell. Lactic dehydrogenase, which catalyzes the reduction of pymvic acid to L-lactic acid exists in five isozymic forms. These are tetramers formed by the association of two polypeptides of equal size H (heart) and M (muscle). 

NUCLEOSIDE MONOPHOSPHATE KINASES CATALYZING PHOSPHORYL GROUP EXCHANGE BETWEEN NUCLEOTIDES WITHOUT PROMOTING HYDROLYSIS... 

Another area of concern involves the inherent nonspecificity of protein kinase-catalyzed phosphorylation in general, especially in broken-cell systems. Often, introduction of a kinase to broken-cell fractions results in the enzyme s catalyzing the phosphorylation of substrates that would not normally be phosphorylated by the kinase in the intact cell. PKG, for example, is often not highly selective in recognizing substrates in vitro and will catalyze the phosphorylation of proteins that are endogenous and physiologi-... 

Saha, A.K. Dowling, J.N. Mukhopadhyay, N.K. Glew, R.H. Legionella mic-dadei protein kinase catalyzes phosphorylation of tubulin and phosphati-dylinositol. J. BacterioL, 171, 5103-5110 (1989)... 

EXAMPLE 6.23 PL-Cy (see Sec. 6.4) binds to phosphotyrosine residues on the cytoplasmic domains of growth factor receptors via its SH2 domains. This has two consequences. First, it becomes activated by receptor tyrosine protein kinase-catalyzed phosphorylation. Second, PL-Cy is normally found in the cytoplasm. Its recruitment to the cytoplasmic domains of growth factor receptors places it in proximity with the cytoplasmic leaflet of the cell membrane, where it is able to catalyze cleavage of the membrane phospholipid phosphatidyl inositol bisphosphate to yield two products, IP3 and DAG (see Fig. 6-6). 

The signaling pathways described above stimulate cell division. However, cell proliferation requires cell enlargement (cell growth) as well. Signaling pathways that involve phosphatidylinositol-3-kinase (Pl-3-kinase) play a role in this. Activated Pl-3-kinases catalyze phosphorylation of inositol phospholipids at the 3 position of the inositol ring to generate lipids called P1(3,4)P2 or P1(3,4,5)P3. 

The ability of some Cr(III) complexes to activate ATP dependent kinases (496, 497) may seem surprising, as stable Cr -ATP complexes (such as XIV in Chart 2 one of the many possible stereoisomers is shown) (629) are well known to act as kinase inhibitors. Chromium(III) in these complexes is a kinetically inert replacement of a natural ATP binding ion, Mg(II) (629-631). However, a Cr(III) complex, [Cr(NH3)5(OH)] +, has recently been shown to promote the in vitro phosphorylation by ATP of the hydroxo groups of Ser and Thr residues in bovine serum albumin at pH 7.4, while several other Cr(III) complexes with N- and O-donor ligands did not possess such activity (632). The proposed phosphorylation mechanism (Scheme 12) (632) involves the formation of a ternary complex of Cr(III), ATP, and the amino acid residue. This mechanism may be related to the kinase-catalyzed phosphorylation of protein Tyr residues. 

One of the most subtle stereospeciflcity of enzymes relates to their ability to distinguish between two identical atoms/groups (proR versus proS) bonded to a carbon atom in prochiral stereospeciflcity (Hanson and Rose, 1975). For example, yeast fermentative glycerol kinase catalyzes phosphorylation of only one (proS) of the two chemically identical primary hydroxyl groups to yield L-glycerol-3-phosphate ... 

The data described above suggest that the ADP-ribosylated arginine may be sequenced near serine residue 38 which is phosphorylated by cAMP-dependent protein kinase (Fig. 3). In the experiment of protein kinase-catalyzed phosphorylation of synthetic peptide, Zetterqvist et al. [9] and Kemp et al. [10] proposed that two arginine residues are necessary at the N-terminal side of phosphate-accepting serine residue. Therefore, we speculated that the ADP-ribosylation may influence the cAMP-dependent protein kinase activity. Actually, we found that when whole histones from calf thymus were... 

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