Matches in SemOpenAlex for { <https://semopenalex.org/work/W2743092628> ?p ?o ?g. }
- W2743092628 abstract "C-terminal Src kinase (Csk) and Csk-homologous kinase (Chk) are the major endogenous inhibitors of Src-family kinases (SFKs). They employ two mechanisms to inhibit SFKs. First, they phosphorylate the C-terminal tail tyrosine which stabilizes SFKs in a closed inactive conformation by engaging the SH2 domain in cis. Second, they employ a non-catalytic inhibitory mechanism involving direct binding of Csk and Chk to the active forms of SFKs that is independent of phosphorylation of their C-terminal tail. Csk and Chk are co-expressed in many cell types. Contributions of the two mechanisms towards the inhibitory activity of Csk and Chk are not fully clear. Furthermore, the determinants in Csk and Chk governing their inhibition of SFKs by the non-catalytic inhibitory mechanism are yet to be defined. We determined the contributions of the two mechanisms towards the inhibitory activity of Csk and Chk both in vitro and in transduced colorectal cancer cells. Specifically, we assayed the catalytic activities of Csk and Chk in phosphorylating a specific peptide substrate and a recombinant SFK member Src. We employed surface plasmon resonance spectroscopy to measure the kinetic parameters of binding of Csk, Chk and their mutants to a constitutively active mutant of the SFK member Hck. Finally, we determined the effects of expression of recombinant Chk on anchorage-independent growth and SFK catalytic activity in Chk-deficient colorectal cancer cells. Our results revealed Csk as a robust enzyme catalysing phosphorylation of the C-terminal tail tyrosine of SFKs but a weak non-catalytic inhibitor of SFKs. In contrast, Chk is a poor catalyst of SFK tail phosphorylation but binds SFKs with high affinity, enabling it to efficiently inhibit SFKs with the non-catalytic inhibitory mechanism both in vitro and in transduced colorectal cancer cells. Further analyses mapped some of the determinants governing this non-catalytic inhibitory mechanism of Chk to its kinase domain. SFKs are activated by different upstream signals to adopt multiple active conformations in cells. SFKs adopting these conformations can effectively be constrained by the two complementary inhibitory mechanisms of Csk and Chk. Furthermore, the lack of this non-catalytic inhibitory mechanism accounts for SFK overactivation in the Chk-deficient colorectal cancer cells." @default.
- W2743092628 created "2017-08-17" @default.
- W2743092628 creator A5021955942 @default.
- W2743092628 creator A5025610952 @default.
- W2743092628 creator A5031778162 @default.
- W2743092628 creator A5033241649 @default.
- W2743092628 creator A5033467236 @default.
- W2743092628 creator A5038232997 @default.
- W2743092628 creator A5041859681 @default.
- W2743092628 creator A5051930564 @default.
- W2743092628 creator A5053070364 @default.
- W2743092628 creator A5061700388 @default.
- W2743092628 creator A5079759294 @default.
- W2743092628 creator A5082020358 @default.
- W2743092628 creator A5082788029 @default.
- W2743092628 creator A5085160372 @default.
- W2743092628 creator A5089222354 @default.
- W2743092628 date "2017-08-07" @default.
- W2743092628 modified "2023-10-15" @default.
- W2743092628 title "Csk-homologous kinase (Chk) is an efficient inhibitor of Src-family kinases but a poor catalyst of phosphorylation of their C-terminal regulatory tyrosine" @default.
- W2743092628 cites W104341128 @default.
- W2743092628 cites W1493020321 @default.
- W2743092628 cites W1543765889 @default.
- W2743092628 cites W1549736588 @default.
- W2743092628 cites W1553517909 @default.
- W2743092628 cites W1594706458 @default.
- W2743092628 cites W1606556342 @default.
- W2743092628 cites W160967443 @default.
- W2743092628 cites W1963570775 @default.
- W2743092628 cites W1966680042 @default.
- W2743092628 cites W1972035895 @default.
- W2743092628 cites W1975091728 @default.
- W2743092628 cites W1977455794 @default.
- W2743092628 cites W1978592925 @default.
- W2743092628 cites W1983228354 @default.
- W2743092628 cites W1986366957 @default.
- W2743092628 cites W1987919961 @default.
- W2743092628 cites W1991683855 @default.
- W2743092628 cites W1992009506 @default.
- W2743092628 cites W1999565970 @default.
- W2743092628 cites W2000985502 @default.
- W2743092628 cites W2005076200 @default.
- W2743092628 cites W2014096863 @default.
- W2743092628 cites W2014397920 @default.
- W2743092628 cites W2015412259 @default.
- W2743092628 cites W2016742702 @default.
- W2743092628 cites W2017466223 @default.
- W2743092628 cites W2019232538 @default.
- W2743092628 cites W2019954887 @default.
- W2743092628 cites W2021181797 @default.
- W2743092628 cites W2023075172 @default.
- W2743092628 cites W2026522709 @default.
- W2743092628 cites W2026623398 @default.
- W2743092628 cites W2027207299 @default.
- W2743092628 cites W2030565228 @default.
- W2743092628 cites W2034675561 @default.
- W2743092628 cites W2034716886 @default.
- W2743092628 cites W2039135332 @default.
- W2743092628 cites W2041600623 @default.
- W2743092628 cites W2044831051 @default.
- W2743092628 cites W2046163031 @default.
- W2743092628 cites W2048342162 @default.
- W2743092628 cites W2048633418 @default.
- W2743092628 cites W2050747691 @default.
- W2743092628 cites W2051717156 @default.
- W2743092628 cites W2052976240 @default.
- W2743092628 cites W2053943711 @default.
- W2743092628 cites W2054466658 @default.
- W2743092628 cites W2056661805 @default.
- W2743092628 cites W2062256468 @default.
- W2743092628 cites W2063705353 @default.
- W2743092628 cites W2065289702 @default.
- W2743092628 cites W2065587675 @default.
- W2743092628 cites W2070696612 @default.
- W2743092628 cites W2073076702 @default.
- W2743092628 cites W2074448914 @default.
- W2743092628 cites W2075265463 @default.
- W2743092628 cites W2075564615 @default.
- W2743092628 cites W2084412270 @default.
- W2743092628 cites W2087937207 @default.
- W2743092628 cites W2089291239 @default.
- W2743092628 cites W2097531007 @default.
- W2743092628 cites W2114453006 @default.
- W2743092628 cites W2125747506 @default.
- W2743092628 cites W2131856634 @default.
- W2743092628 cites W2132663758 @default.
- W2743092628 cites W2134884900 @default.
- W2743092628 cites W2136372437 @default.
- W2743092628 cites W2139553176 @default.
- W2743092628 cites W2141091417 @default.
- W2743092628 cites W2145137278 @default.
- W2743092628 cites W2148006813 @default.
- W2743092628 cites W2156480395 @default.
- W2743092628 cites W2158853280 @default.
- W2743092628 cites W2164557298 @default.
- W2743092628 cites W2229800306 @default.
- W2743092628 cites W2289265939 @default.
- W2743092628 cites W2325375737 @default.
- W2743092628 cites W2418423782 @default.
- W2743092628 cites W2466032192 @default.