Mechanoenzymatics of titin kinase Export

@article{citeulike:3196630, abstract = {10.1073/pnas.0805034105 Biological responses to mechanical stress require strain-sensing molecules, whose mechanically induced conformational changes are relayed to signaling cascades mediating changes in cell and tissue properties. In vertebrate muscle, the giant elastic protein titin is involved in strain sensing via its C-terminal kinase domain (TK) at the sarcomeric M-band and contributes to the adaptation of muscle in response to changes in mechanical strain. TK is regulated in a unique dual autoinhibition mechanism by a C-terminal regulatory tail, blocking the ATP binding site, and tyrosine autoinhibition of the catalytic base. For access to the ATP binding site and phosphorylation of the autoinhibitory tyrosine, the C-terminal autoinhibitory tail needs to be removed. Here, we use AFM-based single-molecule force spectroscopy, molecular dynamics simulations, and enzymatics to study the conformational changes during strain-induced activation of human TK. We show that mechanical strain activates ATP binding before unfolding of the structural titin domains, and that TK can thus act as a biological force sensor. Furthermore, we identify the steps in which the autoinhibition of TK is mechanically relieved at low forces, leading to binding of the cosubstrate ATP and priming the enzyme for subsequent autophosphorylation and substrate turnover.}, address = {Chair for Applied Physics, Center for Integrated Protein Science Munich and Center for Nanoscience, Ludwig-Maximilians-Universit\"{a}t M\"{u}nchen, 80799 Munich, Germany;}, author = {Puchner, Elias M. and Alexandrovich, Alexander and Kho, Ay L. and Hensen, Ulf and Sch\~{A}¤fer, Lars V. and Brandmeier, Birgit and Gr\~{A}¤ter, Frauke and Grubm\~{A}¼ller, Helmut and Gaub, Hermann E. and Gautel, Mathias}, citeulike-article-id = {3196630}, citeulike-linkout-0 = {http://dx.doi.org/10.1073/pnas.0805034105}, citeulike-linkout-1 = {http://www.pnas.org/cgi/content/abstract/105/36/13385}, citeulike-linkout-2 = {http://view.ncbi.nlm.nih.gov/pubmed/18765796}, citeulike-linkout-3 = {http://www.hubmed.org/display.cgi?uids=18765796}, day = {9}, doi = {10.1073/pnas.0805034105}, issn = {1091-6490}, journal = {Proceedings of the National Academy of Sciences}, keywords = {force-probe-md, single-molecule-methods}, month = {September}, number = {36}, pages = {13385--13390}, posted-at = {2008-09-05 04:03:48}, priority = {3}, title = {Mechanoenzymatics of titin kinase}, url = {http://dx.doi.org/10.1073/pnas.0805034105}, volume = {105}, year = {2008} }

TY - JOUR ID - citeulike:3196630 L3 - citeulike-article-id:3196630 N2 - 10.1073/pnas.0805034105 Biological responses to mechanical stress require strain-sensing molecules, whose mechanically induced conformational changes are relayed to signaling cascades mediating changes in cell and tissue properties. In vertebrate muscle, the giant elastic protein titin is involved in strain sensing via its C-terminal kinase domain (TK) at the sarcomeric M-band and contributes to the adaptation of muscle in response to changes in mechanical strain. TK is regulated in a unique dual autoinhibition mechanism by a C-terminal regulatory tail, blocking the ATP binding site, and tyrosine autoinhibition of the catalytic base. For access to the ATP binding site and phosphorylation of the autoinhibitory tyrosine, the C-terminal autoinhibitory tail needs to be removed. Here, we use AFM-based single-molecule force spectroscopy, molecular dynamics simulations, and enzymatics to study the conformational changes during strain-induced activation of human TK. We show that mechanical strain activates ATP binding before unfolding of the structural titin domains, and that TK can thus act as a biological force sensor. Furthermore, we identify the steps in which the autoinhibition of TK is mechanically relieved at low forces, leading to binding of the cosubstrate ATP and priming the enzyme for subsequent autophosphorylation and substrate turnover. IS - 36 JF - Proceedings of the National Academy of Sciences SN - 1091-6490 AD - Chair for Applied Physics, Center for Integrated Protein Science Munich and Center for Nanoscience, Ludwig-Maximilians-Universität München, 80799 Munich, Germany; EP - 13390 TI - Mechanoenzymatics of titin kinase VL - 105 SP - 13385 KW - force-probe-md KW - single-molecule-methods AU - Puchner, Elias AU - Alexandrovich, Alexander AU - Kho, Ay AU - Hensen, Ulf AU - Schäfer, Lars AU - Brandmeier, Birgit AU - Gräter, Frauke AU - Grubmüller, Helmut AU - Gaub, Hermann AU - Gautel, Mathias PY - 2008/09/09/ UR - http://dx.doi.org/10.1073/pnas.0805034105 ER -