Substrate phosphorylation

In many instances, substrate phosphorylation is not coupled to oxidation of the electron donor source by the bacteria therefore, growth will result from oxidative phosphorylation with electrons energizing the plasma membrane for ATP production according to the chemiosmotic system. A list of bacteria displaying dissimilatory reduction where growth is coupled to reduction of metaPmetalloid electron acceptors is given in Table 16.4. 

Fig. 8.3. Ligand-induced autophosphorylation and substrate phosphorylation of receptor tyrosine kinases. The tyrosine kinase domain of the receptor tyrosine kinase is activated by ligand binding. Consequently, autophosphorylation and/or phosphorylation of substrate proteins takes place. The substrate proteins possess specific phosphotyrosine binding domains (SH2 in the figure or FTP domains, see 8.2), which bind to phosphate residues formed in the process of autophosphorylation.

ATP -I- synapsin <1, 2> (<1> brain synapsin best substrate of chicken gizzard caldesmon kinase [1] <1> brain synapsin best substrate, phosphorylated at 950% the rate of caldesmon [5]) (Reversibility <1,2>... 

ATP -I- peptide <1> (<1> monophosphorylated [7] <1> containing sites phosphorylated in rhodopsin [9, 23] <1> less amount of phosphoryl group incorporation than of rhodopsin [9] <1> corresponding to the C-terminus and loop 5-6 of opsin, poor substrates, phosphorylates serine and threonine residues in each peptide [12] <1> acid-rich peptides, RK prefers acid residues localized to the C-terminal side of the serine [15, 23] <1> low catalytic efficiency of RK toward a peptide containing its major autophosphorylation site [27] <1> acidic peptides, stimulated by photo-lyzed rhodopsin, K-491 of RK participates in substrate binding [33]) (Reversibility <1> [7, 9, 12, 15, 22, 23, 27, 33, 36]) [7, 9, 12, 15, 22, 23, 27, 33, 36]... 

Rose SD, Lejen T, Zhang L et al (2001) Chromaffin cell F-actin disassembly and potentiation of catecholamine release in response to protein kinase C activation by phorbol esters is mediated through myristoylated alanine-rich C kinase substrate phosphorylation. J Biol Chem 276 36757-63... 

Microorganisms, which contain the enzymes APS-reductase, ADP-sulfurylase, adenylate kinase and/or ATP-sulfurylase have a certain advantage over those lacking these enzymes, because in addition to photophosphorylation they can also perform a substrate phosphorylation. 

Antibodies coated onto MTP wells capture kinase or phosphatase substrate phosphorylation state is detected by anti-phosphopeptide antibody coupled to detector dye can be read by time-resolved fluorescence (DELFIA) technique... 

An interesting observation was made when VPl and the minor structural protein VP2 were coexpressed in insect cells. First, immunoprecipitation analyses demonstrated a physical association between VPl and VP2, which was not surprising given the incorporation of small amounts of this protein into native virions. Second, and more interesting, the phosphorylation pattern of VPl changed in the presence of VP2. When expressed in insect cells, VPl is phosphorylated predominantly on serine, whereas in virus-infected mouse cells there is a 2 1 phosphothreonine phosphoserine ratio. On coexpression of VP2, the nonphysiologic serine phosphorylation was reduced and phosphorylation of Thr-63, the same residue that is phosphorylated in infected mouse cells, was detected (Li et al., 1995). Thus, coexpression of the two proteins in insect cells led to proper substrate phosphorylation. 

Richard DE, Berra E, Pouyssegur J. Nonhypoxic pathway mediates the induction of hypoxia-inducible factor 1 alpha in vascular smooth muscle cells. J. Biol. Chem. 2000 275 26765-26771. Lancaster DE, McNeill LA, McDonough MA, Aplin RT, Hewitson KS, Pugh CW, Ratcliffe PJ, Schofield CJ. Disruption of dimerisation and substrate phosphorylation inhibit factor inhibiting hypoxia-inducible factor (FIH) activity. Biochem. J. 2004 (383) 429-427. 

In most cases, the effect of cyclic AMP has been to increase the activity of protein kinase, but instances have been found in which the cyclic nucleotide decreased the protein kinase activity. In these cases the level of substrate phosphorylation was lower in the presence than in the absence of cyclic AMP. Such a net decrease in the level of phosphorylation of a protein substrate may result either from a decrease in the activity of a protein kinase or from an increase in the activity of a protein phosphatase, or both [81]. Cyclic AMP-inhibited protein kinases have been described [82]. 

Which of the following enzymatic reactions is an example of substrate phosphorylation ... 

In this complex reaction catalyzed by succinyl-CoA synthase (succinate thiokinase), the energy-rich thioester linkage of succinyl-CoA is hydrolyzed with release of free energy that is conserved in the substrate phosphorylation of GDP with phosphate to form GTP ... 

The exact mechanism of IFN-a activity in CML is unknown, but is complex with multiple effects on cellular function. Some of the proposed alterations include changes in gene transcription, substrate phosphorylation, antigen presentation, and apoptosis. ... 

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