Repetitive deformation and pressure activate small bowel and colonic mucosal tyrosine kinase activity in vivo

Metabolism ◽  
2002 ◽  
Vol 51 (12) ◽  
pp. 1525-1527 ◽  
Author(s):  
Marc D. Basson ◽  
Christopher P. Coppola
1988 ◽  
Vol 263 (2) ◽  
pp. 988-993 ◽  
Author(s):  
S R Coughlin ◽  
P J Barr ◽  
L S Cousens ◽  
L J Fretto ◽  
L T Williams

1991 ◽  
Vol 11 (3) ◽  
pp. 1553-1565 ◽  
Author(s):  
J R McWhirter ◽  
J Y Wang

Chronic myelogenous leukemia and one type of acute lymphoblastic leukemia are characterized by a 9;22 chronosome translocation in which 5' sequences of the bcr gene become fused to the c-abl proto-oncogene. The resulting chimeric genes encode bcr/abl fusion proteins which have deregulated tyrosine kinase activity and appear to play an important role in induction of these leukemias. A series of bcr/abl genes were constructed in which nested deletions of the bcr gene were fused to the c-abl gene. The fusion proteins encoded by these genes were assayed for autophosphorylation in vivo and for differences in subcellular localization. Our results demonstrate that bcr sequences activate two functions of c-abl; the tyrosine kinase activity and a previously undescribed microfilament-binding function. Two regions of bcr which activate these functions to different degrees have been mapped: amino acids 1 to 63 were strongly activating and amino acids 64 to 509 were weakly activating. The tyrosine kinase and microfilament-binding functions were not interdependent, as a kinase defective bcr/abl mutant still associated with actin filaments and a bcr/abl mutant lacking actin association still had deregulated kinase activity. Modification of actin filament functions by the bcr/abl tyrosine kinase may be an important event in leukemogenesis.


1990 ◽  
Vol 10 (12) ◽  
pp. 6244-6256 ◽  
Author(s):  
D Dailey ◽  
G L Schieven ◽  
M Y Lim ◽  
H Marquardt ◽  
T Gilmore ◽  
...  

Extracts of bakers' yeast (Saccharomyces cerevisiae) contain protein-tyrosine kinase activity that can be detected with a synthetic Glu-Tyr copolymer as substrate (G. Schieven, J. Thorner, and G.S. Martin, Science 231:390-393, 1986). By using this assay in conjunction with ion-exchange and affinity chromatography, a soluble tyrosine kinase activity was purified over 8,000-fold from yeast extracts. The purified activity did not utilize typical substrates for mammalian protein-tyrosine kinases (enolase, casein, and histones). The level of tyrosine kinase activity at all steps of each preparation correlated with the content of a 40-kDa protein (p40). Upon incubation of the most highly purified fractions with Mn-ATP or Mg-ATP, p40 was the only protein phosphorylated on tyrosine. Immunoblotting of purified p40 or total yeast extracts with antiphosphotyrosine antibodies and phosphoamino acid analysis of 32P-labeled yeast proteins fractionated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that the 40-kDa protein is normally phosphorylated at tyrosine in vivo. 32P-labeled p40 immunoprecipitated from extracts of metabolically labeled cells by affinity-purified anti-p40 antibodies contained both phosphoserine and phosphotyrosine. The gene encoding p40 (YPK1) was cloned from a yeast genomic library by using oligonucleotide probes designed on the basis of the sequence of purified peptides. As deduced from the nucleotide sequence of YPK1, p40 is homologous to known protein kinases, with features that resemble known protein-serine kinases more than known protein-tyrosine kinases. Thus, p40 is a protein kinase which is phosphorylated in vivo and in vitro at both tyrosine and serine residues; it may be a novel type of autophosphorylating tyrosine kinase, a bifunctional (serine/tyrosine-specific) protein kinase, or a serine kinase that is a substrate for an associated tyrosine kinase.


1985 ◽  
Vol 5 (11) ◽  
pp. 3116-3123
Author(s):  
J B Konopka ◽  
O N Witte

The v-abl transforming protein P160v-abl and the P210c-abl gene product of the translocated c-abl gene in Philadelphia chromosome-positive chronic myelogenous leukemia cells have tyrosine-specific protein kinase activity. Under similar assay conditions the normal c-abl gene products, murine P150c-abl and human P145c-abl, lacked detectable kinase activity. Reaction conditions were modified to identify conditions which would permit the detection of c-abl tyrosine kinase activity. It was found that the Formalin-fixed Staphylococcus aureus formerly used for immunoprecipitation inhibits in vitro abl kinase activity. In addition, the sodium dodecyl sulfate and deoxycholate detergents formerly used in the cell lysis buffer were found to decrease recovered abl kinase activity. The discovery of assay conditions for c-abl kinase activity now makes it possible to compare P150c-abl and P145c-abl kinase activity with the altered abl proteins P160v-abl and P210c-abl. Although all of the abl proteins have in vitro tyrosine kinase activity, they differ in the way they utilize themselves as substrates in vitro. Comparison of in vitro and in vivo tyrosine phosphorylation sites of the abl proteins suggests that they function differently in vivo. The development of c-abl kinase assay conditions should be useful in elucidating c-abl function.


1988 ◽  
Vol 8 (8) ◽  
pp. 3510-3517
Author(s):  
S Giordano ◽  
M F Di Renzo ◽  
R Ferracini ◽  
L Chiadò-Piat ◽  
P M Comoglio

A protein with an Mr of 145,000 (p145) was detected by antibodies to phosphotyrosine by Western blot (immunoblot) analysis. This protein was phosphorylated on tyrosine in a gastric carcinoma cell line. In cells that were metabolically labeled with 32Pi, this protein was phosphorylated on tyrosine and serine. p145 is a cysteine-rich transmembrane glycoprotein. The extracellular domain could be labeled by 125I under nonpermeating conditions and was cleaved by mild trypsin treatment of intact cells. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis under nonreducing conditions revealed a shift of p145 mobility to an apparent Mr of 190,000. After immunoprecipitation with phosphotyrosine antibodies, p145 displayed a strong associated protein kinase activity in vitro, becoming phosphorylated on tyrosine. There was no immunological cross-reaction between p145 and known tyrosine kinases. Both in vivo and in vitro tyrosine phosphorylations were unaffected by the addition of known growth factors. However, p145 was rapidly dephosphorylated in vivo when cells were exposed to low pH, a condition that is known to dissociate ligands from their receptors. These data suggest that p145 is associated with a protein tyrosine kinase activity which, in the tumor cell line studied, is activated by an as yet unidentified factor.


1990 ◽  
Vol 10 (12) ◽  
pp. 6244-6256
Author(s):  
D Dailey ◽  
G L Schieven ◽  
M Y Lim ◽  
H Marquardt ◽  
T Gilmore ◽  
...  

Extracts of bakers' yeast (Saccharomyces cerevisiae) contain protein-tyrosine kinase activity that can be detected with a synthetic Glu-Tyr copolymer as substrate (G. Schieven, J. Thorner, and G.S. Martin, Science 231:390-393, 1986). By using this assay in conjunction with ion-exchange and affinity chromatography, a soluble tyrosine kinase activity was purified over 8,000-fold from yeast extracts. The purified activity did not utilize typical substrates for mammalian protein-tyrosine kinases (enolase, casein, and histones). The level of tyrosine kinase activity at all steps of each preparation correlated with the content of a 40-kDa protein (p40). Upon incubation of the most highly purified fractions with Mn-ATP or Mg-ATP, p40 was the only protein phosphorylated on tyrosine. Immunoblotting of purified p40 or total yeast extracts with antiphosphotyrosine antibodies and phosphoamino acid analysis of 32P-labeled yeast proteins fractionated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that the 40-kDa protein is normally phosphorylated at tyrosine in vivo. 32P-labeled p40 immunoprecipitated from extracts of metabolically labeled cells by affinity-purified anti-p40 antibodies contained both phosphoserine and phosphotyrosine. The gene encoding p40 (YPK1) was cloned from a yeast genomic library by using oligonucleotide probes designed on the basis of the sequence of purified peptides. As deduced from the nucleotide sequence of YPK1, p40 is homologous to known protein kinases, with features that resemble known protein-serine kinases more than known protein-tyrosine kinases. Thus, p40 is a protein kinase which is phosphorylated in vivo and in vitro at both tyrosine and serine residues; it may be a novel type of autophosphorylating tyrosine kinase, a bifunctional (serine/tyrosine-specific) protein kinase, or a serine kinase that is a substrate for an associated tyrosine kinase.


1985 ◽  
Vol 5 (11) ◽  
pp. 3116-3123 ◽  
Author(s):  
J B Konopka ◽  
O N Witte

The v-abl transforming protein P160v-abl and the P210c-abl gene product of the translocated c-abl gene in Philadelphia chromosome-positive chronic myelogenous leukemia cells have tyrosine-specific protein kinase activity. Under similar assay conditions the normal c-abl gene products, murine P150c-abl and human P145c-abl, lacked detectable kinase activity. Reaction conditions were modified to identify conditions which would permit the detection of c-abl tyrosine kinase activity. It was found that the Formalin-fixed Staphylococcus aureus formerly used for immunoprecipitation inhibits in vitro abl kinase activity. In addition, the sodium dodecyl sulfate and deoxycholate detergents formerly used in the cell lysis buffer were found to decrease recovered abl kinase activity. The discovery of assay conditions for c-abl kinase activity now makes it possible to compare P150c-abl and P145c-abl kinase activity with the altered abl proteins P160v-abl and P210c-abl. Although all of the abl proteins have in vitro tyrosine kinase activity, they differ in the way they utilize themselves as substrates in vitro. Comparison of in vitro and in vivo tyrosine phosphorylation sites of the abl proteins suggests that they function differently in vivo. The development of c-abl kinase assay conditions should be useful in elucidating c-abl function.


1996 ◽  
Vol 211 (4) ◽  
pp. 339-345 ◽  
Author(s):  
M. K. Younoszai ◽  
V. V. Parekh ◽  
T. C. Stephen ◽  
J. L. Hoffman

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