Muscle-type creatine kinase interacts with central domains of the M-band proteins myomesin and M-protein

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Item Type:	Article
Title:	Muscle-type creatine kinase interacts with central domains of the M-band proteins myomesin and M-protein
Creators Name:	Hornemann, T., Kempa, S., Himmel, M., Hayess, K., Fuerst, D.O. and Wallimann, T.
Abstract:	Muscle-type creatine kinase (MM-CK) is a member of the CK isoenzyme family with key functions in cellular energetics. MM-CK interacts in an isoform-specific manner with the M-band of sarcomeric muscle, where it serves as an efficient intramyofibrillar ATP-regenerating system for the actin-activated myosin ATPase located nearby on both sides of the M-band. Four MM-CK-specific and highly conserved lysine residues are thought to be responsible for the interaction of MM-CK with the M-band. A yeast two-hybrid screen led to the identification of MM-CK as a binding partner of a central portion of myomesin (My7-8). An interaction was observed with domains six to eight of the closely related M-protein but not with several other Ig-like domains, including an M-band domain, of titin. The observed interactions were corroborated and characterised in detail by surface plasmon resonance spectroscopy (BiaCore). In both cases, they were CK isoform-specific and the MM-CK-specific lysine residues (K8. K24, K104 and K115) are involved in this interaction. At pH 6.8, the dissociation constants for the myomesin/MM-CK and the M-protein/MM-CK binding were in the range of 50-100 nM and around 1 microM, respectively. The binding showed pronounced pH-dependence and indicates a dynamic association/dissociation behaviour, which most likely depends on the energy state of the muscle. Our data propose a simple model for the regulation of this dynamic interaction.
Keywords:	Creatine Kinase, Myomesin, M-Protein, Sarcomeric M-Band, Titin, Animals, Chickens
Source:	Journal of Molecular Biology
ISSN:	0022-2836
Publisher:	Academic Press
Volume:	332
Number:	4
Page Range:	877-887
Date:	26 September 2003
Official Publication:	https://doi.org/10.1016/S0022-2836(03)00921-5
PubMed:	View item in PubMed

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