The fully linked HTML version of this article has now been published.
JCS ePress
online publication date 26 Oct 2004
doi: 10.1242/jcs.01501
Research Article
Differential actin binding along the PEVK domain of skeletal muscle titin
Attila Nagy,
Paola Cacciafesta,
László Grama,
András Kengyel,
András Málnási-Csizmadia,
and
Miklós S.Z. Kellermayer*
* Author for correspondence (e-mail: miklos.kellermayer.jr{at}aok.pte.hu)
Parts of the PEVK (Pro-Glu-Val-Lys) domain of the skeletal muscle isoform of the giant intrasarcomeric protein titin have been shown to bind F-actin. However, the mechanisms and physiological function of this are poorly understood. To test for actin binding along PEVK, we expressed contiguous N-terminal (PEVKI), middle (PEVKII), and C-terminal (PEVKIII) PEVK segments of the human soleus muscle isoform. We found a differential actin binding along PEVK in solid-state binding, cross-linking and in vitro motility assays. The order of apparent affinity is PEVKII>PEVKI>PEVKIII. To explore which sequence motifs convey the actin-binding property, we cloned and expressed PEVK fragments with different motif structure: PPAK, polyE-rich and pure polyE fragments. The polyE-containing fragments had a stronger apparent actin binding, suggesting that a local preponderance of polyE motifs conveys an enhanced local actin-binding property to PEVK. The actin binding of PEVK may serve as a viscous bumper mechanism that limits the velocity of unloaded muscle shortening towards short sarcomere lengths. Variations in the motif structure of PEVK might be a method of regulating the magnitude of the viscous drag.
This article has been cited by other articles:

|
 |

|
 |
 
W. A. Linke
Sense and stretchability: The role of titin and titin-associated proteins in myocardial stress-sensing and mechanical dysfunction
Cardiovasc Res,
March 1, 2008;
77(4):
637 - 648.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
P. Bianco, A. Nagy, A. Kengyel, D. Szatmari, Z. Martonfalvi, T. Huber, and M. S. Z. Kellermayer
Interaction Forces between F-Actin and Titin PEVK Domain Measured with Optical Tweezers
Biophys. J.,
September 15, 2007;
93(6):
2102 - 2109.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
L. Fabian, X. Xia, D. V. Venkitaramani, K. M. Johansen, J. Johansen, D. J. Andrew, and A. Forer
Titin in insect spermatocyte spindle fibers associates with microtubules, actin, myosin and the matrix proteins skeletor, megator and chromator
J. Cell Sci.,
July 1, 2007;
120(13):
2190 - 2204.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
K. Ono, R. Yu, K. Mohri, and S. Ono
Caenorhabditis elegans Kettin, a Large Immunoglobulin-like Repeat Protein, Binds to Filamentous Actin and Provides Mechanical Stability to the Contractile Apparatuses in Body Wall Muscle
Mol. Biol. Cell,
June 1, 2006;
17(6):
2722 - 2734.
[Abstract]
[Full Text]
[PDF]
|
 |
|
© The Company of Biologists Ltd 2004