Abstract
BackgroundIntermolecular autophosphorylation at Tyr416 is a conserved mechanism of activation among the members of the Src family of nonreceptor tyrosine kinases. Like several other tyrosine kinases, Src can catalyze the thiophosphorylation of peptide and protein substrates using ATPγS as a thiophosphodonor, although the efficiency of the reaction is low.ResultsHere, we have characterized the ability of Src to auto-thiophosphorylate. Auto-thiophosphorylation of Src at Tyr416 in the activation loop proceeds efficiently in the presence of Ni2+, resulting in kinase activation. Other tyrosine kinases (Ack1, Hck, and IGF1 receptor) also auto-thiophosphorylate in the presence of Ni2+. Tyr416-thiophosphorylated Src is resistant to dephosphorylation by PTP1B phosphatase.ConclusionsSrc and other tyrosine kinases catalyze auto-thiophosphorylation in the presence of Ni2+. Thiophosphorylation of Src occurs at Tyr416 in the activation loop, and results in enhanced kinase activity. Tyr416-thiophosphorylated Src could serve as a stable, persistently-activated mimic of Src.Electronic supplementary materialThe online version of this article (doi:10.1186/s12858-016-0071-z) contains supplementary material, which is available to authorized users.
Highlights
Intermolecular autophosphorylation at Tyr416 is a conserved mechanism of activation among the members of the Src family of nonreceptor tyrosine kinases
Tyr416-thiophosphorylated Src is resistant to dephosphorylation by PTP1B phosphatase, and could serve as a stable, persistently-activated mimic of Src
In our previous studies [16], we showed that the Src family kinase Hck can catalyze thiophosphorylation of a peptide substrate in the presence of CoCl2
Summary
Intermolecular autophosphorylation at Tyr416 is a conserved mechanism of activation among the members of the Src family of nonreceptor tyrosine kinases. Like several other tyrosine kinases, Src can catalyze the thiophosphorylation of peptide and protein substrates using ATPγS as a thiophosphodonor, the efficiency of the reaction is low. Protein and peptide substrates bind in an extended conformation at the entrance to this cleft. Autophosphorylation within the activation loop stabilizes a conformation that allows substrate binding, and promotes kinase activity [1,2,3]. For tyrosine kinases where this has been examined explicitly, autophosphorylation is intermolecular [4,5,6].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
