Esters of phosphoric acid

Plimmer, Robert Henry Aders

doi:10.1042/bj0350461

Cited by 106 publications

(10 citation statements)

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“…This relative increase in phosphotyrosine most likely is. considerably greater than 10-fold; phosphotyrosine is substantially more acid labile than is phosphoserine (21), and thus preferentially hydrolyzed in the hydrolysis of the isolated protein.…”

Section: Resultsmentioning

confidence: 99%

Platelet-derived growth factor stimulates tyrosine-specific protein kinase activity in Swiss mouse 3T3 cell membranes.

Nishimura¹,

Huang²,

Deuel³

1982

Proc. Natl. Acad. Sci. U.S.A.

250

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Platelet-derived growth factor (PDGF) stimulates the incorporation of 32P from [y-32P]ATP into a Mr z170,000 protein by an endogenous tyrosine-specific protein kinase in membrane preparations of Swiss mouse 3T3 cells. Epidermal growth factor (EGF), but not fibroblast growth factor (FGF) or insulin, stimulates limited incorporation of 32P into a protein of similar molecular weight. The ligand concentration required for halfmaximal activity (S0 5) for PDGF stimulation of phosphorylation is 50 ng/ml; saturation is achieved at 300 ng/ml. The SO.5 for ATP is 15 jiM. Mg2' or Mn2+ is required for protein kinase activity. Stimulation by PDGF results in the preferential phosphorylation of tyrosine residues in this Mr =170,000 membrane protein. The Mr "170,000 protein can be resolved into Mr 4180,000 and 160,000 components in 4% NaDodSO4 gels. PDGF stimulates 32P incorporation preferentially into the Mr 4180,000 and less extensively into the Mr '160,000 protein. EGF stimulates 32p incorporation predominantly into a protein of Mr '160,000. The similarity of PDGF and EGF in stimulating phosphotyrosine-specific protein Idnase activity and the stimulation of a similar activity by viral transformation (src) genes suggest that a common mechanism may exist for the phenotypic expression of increased DNA synthesis and cell growth stimulated by these separate factors.The mechanisms whereby polypeptide growth factors stimulate target cells to synthesize DNA and to enter cell division remain unresolved. Recently, epidermal growth factor (EGF) was shown to stimulate the phosphorylation of Mr 150,000 and Mr 170,000 membrane proteins in A431 epidermal carcinoma cells (1, 2). Phosphotyrosine has been identified in hydrolysates of the protein phosphorylated by the membrane protein kinase activity expressed in target cells after exposure to EGF; this protein has been isolated and shown to contain protein kinase activity itself and to be associated with EGF binding activity (3)(4)(5)(6). This EGF stimulation of protein kinase activity is of additional interest because of recent findings that the product of the Rous sarcoma transformation gene (src) is a protein kinase that also specifically phosphorylates tyrosine residues in target proteins (7-10).We recently purified the platelet-derived growth factor (PDGF) to apparent homogeneity. Two separate, equally active proteins-PDGF I and PDGF II-were separated and found to be glycoproteins of different carbohydrate composition but with essentially identical amino acid compositions (11,12 Ficoll (wt/vol). After centrifugation at 100,000 X g for 8 hr, the membrane fraction at the interface was collected, suspended in 10 mM Hepes at pH 7.4, and pelleted by centrifugation at 39,000 X g for 20 min. Protein was determined as described by Lowry et aL (17 The publication costs ofthis article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U. S. C. §1734 solely to indicate this fact.4304 Biochemistry: Nishimura e...

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Section: Resultsmentioning

confidence: 99%

Platelet-derived growth factor stimulates tyrosine-specific protein kinase activity in Swiss mouse 3T3 cell membranes.

Nishimura¹,

Huang²,

Deuel³

1982

Proc. Natl. Acad. Sci. U.S.A.

250

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“…Samples of aspartic acid, O-phosphoserine and O-phosphothreonine (Sigma Chemical Co., St. Louis, MO, U.S.A.) were similarly chromatographed and hydrolysed to confirm the adequacy of these procedures (Spector & Glimcher, 1973 Other 0-phospho amino acids. Samples of the proteins were hydrolysed in 4M-HCl at 105°C for 6h and chromatographed on the Beckman 121 M automatic amino acid analyser and on Dowex 1 (Cl-form) (Glimcher & Krane, 1964a) and compared with standards of O-phosphotyrosine, 0-phosphohydroxyproline and O-phosphohydroxylysine prepared as described by Plimmer (1941), and those purchased from Vega-Fox Chemical Co. (Tucson, AZ, U.S.A.).…”

Section: Analytical Determinationsmentioning

confidence: 99%

Identification of organic phosphorus covalently bound to collagen and non-collagenous proteins of chicken-bone matrix. The presence of O-phosphoserine and O-phosphothreonine in non-collagenous proteins, and their absence from phosphorylated collagen

Cohen-Solal

Lian

Kossiva

et al. 1979

Biochemical Journal

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Non-collagenous phosphoproteins, almost all of which can be extracted in EDTA at neutral pH in the presence of proteinase inhibitors, are identified in the matrix of chicken bone, and are therefore not covalently bound to collagen. Similarly, all the peptides containing y-carboxyglutamic acid are present in the EDTA extract and none in the insoluble residue, confirming that none is covalently linked to chicken bone collagen. However, organic phosphorus is also found to be present in chicken bone collagen, principally in the a2-chains. Of the total protein-bound organic phosphorus present in chicken bone matrix, approx. 80 % is associated with the non-collagenous proteins and 20 % with collagen. The soluble non-collagenous proteins contain both O-phosphoserine and 0-phosphothreonine and these account for essentially all of their organic phosphorus content. In contrast, collagen contains neither 0-phosphoserine nor 0-phosphothreonine. Indeed, no phosphorylated hydroxy amino acid, phosphoamidated amino acid or phosphorylated sugar could be identified in purified components of collagen, which contain approximately four to five atoms of organic phosphorus per molecule of collagen. Peptides containing organic phosphorus were isolated from partial acid hydrolysates and enzymic digests of purified collagen components, which contain an as-yet-unidentified cationic amino acid. These data, the very high concentrations of glutamic acid in the phosphorylated peptides, and the pH-stability of the organic phosphorus moiety in intact collagen chains strongly suggest that at least part of the organic phosphorus in collagen is present as phosphorylated glutamic acid. This would indicate that the two major chemically different protein fractions in chicken bone matrix that contain organic phosphorus may represent two distinct metabolic pools of organic phosphorus under separate biological control.Phosphoproteins have been identified as part of the non-collagenous components of the organic matrices of mineralized vertebrate tissues such as enamel (Seyer & Glimcher, 1971;Papas et al., 1977;Seyer & Glimcher, 1977a), dentine Veis & Perry, 1967;Butler, 1972;Butler et al., 1972;Veis et al., 1972;Carmichael & Dodd, 1973;Pieri et al., 1975;Menanteau et al., 1977) and bone (Spector & Glimcher, 1972;Shuttleworth & Veis, 1972) [see Leaver et al. (1975b) for a review]. There still exists, however, at least two major points of controversy with regard to bone and dentine: (1) how much, if any, of the phosphorylated protein(s) is covalently bound to the collagen, and (2), if present, Abbreviation used: P,, organic phosphate. * Present address: I.N.S.E.R.M. U12 and U18, Hc6pital des Enfants malades, Paris, France. t To whom requests for reprints should be addressed. Vol. 177 the nature of the organic phosphate moiety covalently bound to the collagen.Although evidence has been presented that none of the phosphoprotein is covalently bound to the collagen of rat dentine (Butler, 1972;Butler et al., 1972Butler et al., , 1976, equally substantia...

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“…Duplicate reaction mixes were electrophoresed on NaDodSO4/polyacrylamide gels, and one set was treated with alkali (1 M KOH). This treatment was performed to hydrolyze the phosphoserine and phosphothreonine residues, since the phosphodiester linkage to tyrosine residues is known to be more resistant to alkali treatment than phosphothreonine and phosphoserine (23,30,31). The results of this experiment are shown in Fig.…”

mentioning

confidence: 99%

Blood platelets express high levels of the pp60c-src-specific tyrosine kinase activity.

Golden¹,

Nemeth²,

Brugge³

1986

Proc. Natl. Acad. Sci. U.S.A.

310

141

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We have examined human and rabbit blood platelets for expression of pp6oc-,rc, the normal cellular homolog of the transforming protein of Rous sarcoma virus. pp6Oc8rc kinase activity was determined by an immunecomplex kinase assay that uses enolase as the substrate, and pp6srC protein levels were determined by an immunoblot assay. Lysates from platelets expressed high levels of pp60c-rc-specific kinase activity and pp6O4' protein compared to the levels found in other tissues. pp6Ocsrc was also found to be one of the major proteins phosphorylated in vitro in membranes isolated from platelets. Multiple with the addition of NaDodSO4 sample buffer and then subjected to electrophoresis on 7.5% NaDodSO4/polyacrylamide gels as described by Laemmli (19). The dried gels were Abbreviations: RSV, Rous sarcoma virus; PBL, peripheral blood lymphocyte(s); mAb, monoclonal antibody. 852The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact.

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Esters of phosphoric acid

Cited by 106 publications

References 1 publication

Platelet-derived growth factor stimulates tyrosine-specific protein kinase activity in Swiss mouse 3T3 cell membranes.

Platelet-derived growth factor stimulates tyrosine-specific protein kinase activity in Swiss mouse 3T3 cell membranes.

Identification of organic phosphorus covalently bound to collagen and non-collagenous proteins of chicken-bone matrix. The presence of O-phosphoserine and O-phosphothreonine in non-collagenous proteins, and their absence from phosphorylated collagen

Blood platelets express high levels of the pp60c-src-specific tyrosine kinase activity.

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