Journal
JOURNAL OF BIOLOGICAL CHEMISTRY
Volume 276, Issue 30, Pages 28164-28170Publisher
AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
DOI: 10.1074/jbc.M104161200
Keywords
-
Categories
Funding
- NHLBI NIH HHS [HL 57900, HL 31950, HL 48728] Funding Source: Medline
- NIAMS NIH HHS [AR 27214] Funding Source: Medline
Ask authors/readers for more resources
Talin links integrin beta cytoplasmic domains to the actin cytoskeleton and is involved in the clustering and activation of these receptors. To understand how talin recognizes integrin beta cytoplasmic domains, we configured surface plasmon resonance methodology to measure the interaction of talin with the beta (3) integrin cytoplasmic domain. Here we report that the N-terminal similar to 47-kDa talin head domain (talin-H) has a 6-fold higher binding affinity than intact talin for the beta (3) tail. The affinity difference is mainly due to a difference in k(on). Calpain cleavage of intact talin released talin-H and resulted in a 16-fold increase in apparent K-alpha and a 100-fold increase in apparent k(on). The increase in talin binding after cleavage was greater than predicted for stoichiometric liberation of free talin-H. This additional increase in binding was due to cooperative binding of talin-H and talin rod domain to the beta (3) tail. Talin resembles ERM (ezrin, radixin, moesin) proteins in possessing an N-terminal FERM (band four-point-one, ezrin, radixin, moesin) domain. These data show that the talin FERM domain, like that in the ERM proteins, is masked in the intact molecule. Furthermore, they suggest that talin cleavage by calpain may contribute to the effects of the protease on the clustering and activation of integrins.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available