| Title: |
Tissue Expression and Actin Binding of a Novel N-Terminal Utrophin Isoform |
| Authors: |
Richard A. Zuellig; Beat C. Bornhauser; Ralf Amstutz; Bruno Constantin; Marcus C. Schaub |
| Source: |
Journal of Biomedicine and Biotechnology, Vol 2011 (2011) |
| Publisher Information: |
Hindawi Limited |
| Publication Year: |
2011 |
| Collection: |
Directory of Open Access Journals: DOAJ Articles |
| Subject Terms: |
Biotechnology; TP248.13-248.65; Medicine |
| Description: |
Utrophin and dystrophin present two large proteins that link the intracellular actin cytoskeleton to the extracellular matrix via the C-terminal-associated protein complex. Here we describe a novel short N-terminal isoform of utrophin and its protein product in various rat tissues (N-utro, 62 kDa, amino acids 1–539, comprising the actin-binding domain plus the first two spectrin repeats). Using different N-terminal recombinant utrophin fragments, we show that actin binding exhibits pronounced negative cooperativity (affinity constants K1=∼5×106 and K2=∼1×105 M-1) and is Ca2+-insensitive. Expression of the different fragments in COS7 cells and in myotubes indicates that the actin-binding domain alone binds exlusively to actin filaments. The recombinant N-utro analogue binds in vitro to actin and in the cells associates to the membranes. The results indicate that N-utro may be responsible for the anchoring of the cortical actin cytoskeleton to the membranes in muscle and other tissues. |
| Document Type: |
article in journal/newspaper |
| Language: |
English |
| Relation: |
http://dx.doi.org/10.1155/2011/904547; https://doaj.org/toc/1110-7243; https://doaj.org/toc/1110-7251; https://doaj.org/article/cc228be1f80e49298ea561921693c5e1 |
| DOI: |
10.1155/2011/904547 |
| Availability: |
https://doi.org/10.1155/2011/904547; https://doaj.org/article/cc228be1f80e49298ea561921693c5e1 |
| Accession Number: |
edsbas.FBBAC0A1 |
| Database: |
BASE |