tailieunhanh - Báo cáo khoa học: High levels of structural disorder in scaffold proteins as exemplified by a novel neuronal protein, CASK-interactive protein1

CASK-interactive protein1 is a newly recognized post-synaptic density protein in mammalian neurons. Although its N-terminal region contains several well-known functional domains, its entire C-terminal proline-rich region of 800 amino acids lacks detectable sequence homology to any previously characterized protein. We used multiple techniques for the struc-tural characterization of this region and its three fragments. | High levels of structural disorder in scaffold proteins as exemplified by a novel neuronal protein CASK-interactive proteinl Annamaria Balazs1 Veronika Csizmok2 László Buday1 2 Marianna Rakacs2 Robert Kiss3 Monika Bokor4 Roopesh Udupa2 Kalman Tompa4 and Peter Tompa2 1 Department of MedicalChemistry Semmelweis University MedicalSchool Budapest Hungary 2 BiologicalResearch Center Institute of Enzymology Hungarian Academy of Sciences Budapest Hungary 3 Laboratory of StructuralChemistry and Biology Institute of Chemistry Eotvos Lorand University Budapest Hungary 4 Research Institute for Solid State Physics and Optics Hungarian Academy of Sciences Budapest Hungary Keywords anchor docking post-synaptic density scaffold unstructured Correspondence P. Tompa Institute of Enzymology Biological Research Center Hungarian Academy of Sciences Karolina ut 29 1113 Budapest Hungary Fax 36 1 466 5465 Tel 36 1 279 3143 E-mail tompa@ These authors contributed equally to this work Received 26 February 2009 revised 15 April2009 accepted 12 May 2009 doi CASK-interactive proteinl is a newly recognized post-synaptic density protein in mammalian neurons. Although its N-terminal region contains several well-known functional domains its entire C-terminal proline-rich region of 800 amino acids lacks detectable sequence homology to any previously characterized protein. We used multiple techniques for the structural characterization of this region and its three fragments. By bioinformatics predictions CD spectroscopy wide-line and lH-NMR spectroscopy limited proteolysis and gel filtration chromatography we provided evidence that the entire proline-rich region of CASK-interactive proteinl is intrinsically disordered. We also showed that the proline-rich region is biochemically functional as it interacts with the adaptor protein Abl-interactor-2. To extend the finding of a high level of disorder in this scaffold protein we collected 74 scaffold proteins .