The two isoforms of Lyn display different intramolecular fuzzy complexes with the SH3 domain

The function of the intrinsically disordered Unique domain of the Src family of tyrosine kinases (SFK), where the largest differences between family members are concentrated, remains poorly understood. Recent studies in c-Src have demonstrated that the Unique region forms transient interactions, des...

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Bibliographic Details
Authors: Teixeira, Joao M. C., Fuentes, Héctor, Bielskutė, Stasė, Gairí Tahull, Margarida, Zerko, Szymon, Kozminski, Wiktor, Pons Vallès, Miquel
Format: article
Status:Published version
Publication Date:2018
Country:España
Institution:Universidad de Barcelona
Repository:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/125625
Online Access:https://hdl.handle.net/2445/125625
Access Level:Open access
Keyword:Proteïnes quinases
Ressonància magnètica nuclear
Bioquímica
Protein kinases
Nuclear magnetic resonance
Biochemistry
Description
Summary:The function of the intrinsically disordered Unique domain of the Src family of tyrosine kinases (SFK), where the largest differences between family members are concentrated, remains poorly understood. Recent studies in c-Src have demonstrated that the Unique region forms transient interactions, described as an intramolecular fuzzy complex, with the SH3 domain and suggested that similar complexes could be formed by other SFKs. Src and Lyn are members of a distinct subfamily of SFKs. Lyn is a key player in the immunologic response and exists in two isoforms originating from alternative splicing in the Unique domain. We have used NMR to compare the intramolecular interactions in the two isoforms and found that the alternatively spliced segment interacts specifically with the so-called RT-loop in the SH3 domain and that this interaction is abolished when a polyproline ligand binds to the SH3 domain. These results support the generality of the fuzzy complex formation in distinct subfamilies of SFKs and its physiological role, as the naturally occurring alternative splicing modulates the interactions in this complex.