JCB logo
BioLegend: Antibody Reagents
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents
Published 3 September 2001. doi:10.1083/jcb.200104016
This Article
Right arrow Full Text
Right arrow PDF (Full Text)
Right arrow Alert me when this article is cited
Right arrow Citation Map
Services
Right arrow Email this article
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new content in the JCB
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Kulke, M.
Right arrow Articles by Linke, W. A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Kulke, M.
Right arrow Articles by Linke, W. A.
Related Collections
Right arrowRelated Article
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?
© The Rockefeller University Press, 0021-9525/2001/9/1045 $5.00
The Journal of Cell Biology, Volume 154, Number 5, September 3, 2001 1045-1058

Article

 Kettin, a major source of myofibrillar stiffness in Drosophila indirect flight muscle

Michael Kulke1, Ciprian Neagoe1, Bernhard Kolmerer2, Ave Minajeva1, Horst Hinssen3, Belinda Bullard2 and Wolfgang A. Linke1

1 Institute of Physiology and Pathophysiology, University of Heidelberg, D-69120 Heidelberg, Germany
2 European Molecular Biology Laboratory, D-69012 Heidelberg, Germany
3 Biochemical Cell Biology, University of Bielefeld, D-33501 Bielefeld, Germany

Address correspondence to Wolfgang A. Linke, Intitute of Physiology and Pathophysiology, University of Heidelberg, Im Neuenheimerfeld 326, D-69120 Heidelberg, Germany. Tel.: 49-6221-544130. Fax: 49-6221-544049. E-mail: wolfgang.linke{at}urz.uni-heidelberg.de

Kettin is a high molecular mass protein of insect muscle that in the sarcomeres binds to actin and {alpha}-actinin. To investigate kettin's functional role, we combined immunolabeling experiments with mechanical and biochemical studies on indirect flight muscle (IFM) myofibrils of Drosophila melanogaster. Micrographs of stretched IFM sarcomeres labeled with kettin antibodies revealed staining of the Z-disc periphery. After extraction of the kettin-associated actin, the A-band edges were also stained. In contrast, the staining pattern of projectin, another IFM–I-band protein, was not altered by actin removal. Force measurements were performed on single IFM myofibrils to establish the passive length-tension relationship and record passive stiffness. Stiffness decreased within seconds during gelsolin incubation and to a similar degree upon kettin digestion with µ-calpain. Immunoblotting demonstrated the presence of kettin isoforms in normal Drosophila IFM myofibrils and in myofibrils from an actin-null mutant. Dotblot analysis revealed binding of COOH-terminal kettin domains to myosin. We conclude that kettin is attached not only to actin but also to the end of the thick filament. Kettin along with projectin may constitute the elastic filament system of insect IFM and determine the muscle's high stiffness necessary for stretch activation. Possibly, the two proteins modulate myofibrillar stiffness by expressing different size isoforms.

Key Words: connecting filament; titin; muscle mechanics; projectin; PEVK sequence


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?

Related Article

Flight of the titins
Alan W. Dove
J. Cell Biol. 2001 154: 903. [Full Text] [PDF]



This article has been cited by other articles:



  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents