|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | |||||
Journal of Cell Science, Vol 108, Issue 11 3397-3403, Copyright © 1995 by Company of Biologists
JOURNAL ARTICLES |
X Ao and SS Lehrer
Boston Biomedical Research Institute, MA 02114, USA.
Fluorescent phallotoxins such as rhodamine-phalloidin take hours to bind uniformly to thin filaments of skeletal myofibrils, after fast initial binding to both ends of thin filaments. Observation of this process in skeletal and cardiac myofibrils and of the resulting re-distribution of nebulin using anti-nebulin antibody showed that: (1) rhodamine-phalloidin binds uniformly to actin in cardiac myofibrils within minutes, in contrast to skeletal myofibrils; (2) overnight pre-incubation of skeletal myofibrils with phalloidin results in uniform initial binding of rhodamine-phalloidin and a changed nebulin localization; (3) pre-incubation of skeletal myofibrils with Ca(2+)-calmodulin results in uniform initial binding of rhodamine-phalloidin; (4) the binding of rhodamine-phalloidin to actin in skeletal myofibrils is unidirectional, i.e. the fluorescence of incorporated rhodamine-phalloidin moves from the pointed ends where it is bound initially toward the barbed end at the Z-band; (5) the unidirectional binding of rhodamine-phalloidin results in redistribution of nebulin, i.e. the initial fluorescent bands associated with the epitopes of bound nebulin antibody change to a single band located close to Z-line. These results indicate that nebulin inhibits rhodamine-phalloidin binding to actin and suggests that the unidirectional rhodamine-phalloidin binding may be due to cooperative competitive binding, i.e. phalloidin 'unzips' nebulin starting from the pointed ends of the thin filaments.
This article has been cited by other articles:
![]() |
A. Kontrogianni-Konstantopoulos, M. A. Ackermann, A. L. Bowman, S. V. Yap, and R. J. Bloch Muscle Giants: Molecular Scaffolds in Sarcomerogenesis Physiol Rev, October 1, 2009; 89(4): 1217 - 1267. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. T. Pappas, N. Bhattacharya, J. A. Cooper, and C. C. Gregorio Nebulin Interacts with CapZ and Regulates Thin Filament Architecture within the Z-Disc Mol. Biol. Cell, May 1, 2008; 19(5): 1837 - 1847. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Ojima, Z.X. Lin, M.-L. Bang, S. Holtzer, R. Matsuda, S. Labeit, H.L. Sweeney, and H. Holtzer Distinct Families of Z-Line Targeting Modules in the Cooh-Terminal Region of Nebulin J. Cell Biol., August 7, 2000; 150(3): 553 - 566. [Abstract] [Full Text] [PDF] |
||||
![]() |
A Almenar-Queralt, C. Gregorio, and V. Fowler Tropomodulin assembles early in myofibrillogenesis in chick skeletal muscle: evidence that thin filaments rearrange to form striated myofibrils J. Cell Sci., January 4, 1999; 112(8): 1111 - 1123. [Abstract] [PDF] |
||||
![]() |
A. S. McElhinny, B. Kolmerer, V. M. Fowler, S. Labeit, and C. C. Gregorio The N-terminal End of Nebulin Interacts with Tropomodulin at the Pointed Ends of the Thin Filaments J. Biol. Chem., January 5, 2001; 276(1): 583 - 592. [Abstract] [Full Text] [PDF] |
||||