The presence of two skeletal muscle alpha-actinins correlates with troponin-tropomyosin expression and Z-line width.
Year: 1985
Type: article
Abstract: Two species of alpha-actinin from rabbit fast skeletal muscles were identified with a monospecific antisera. Designated alpha-actinin1f and alpha-actinin2f, their distribution in muscles does not correlate with histochemically defined fast fiber type. Rather, the presence of each correlates with Z-line width and with the expression of different thin filament Ca2+-regulatory complexes. alpha-Actinin1f is expressed with troponin T 1f-alpha beta tropomyosin, and alpha-actinin2f with troponin T 2f-alpha 2 tropomyosin. CNBr peptide maps show that the fast alpha-actinin species differ in primary structure. In contrast, the slow alpha-actinin is indistinguishable from alpha-actinin1f. Further evidence for the similarity of alpha-actinin1f and slow alpha-actinin comes from electron microscopic studies which show that fibers that express these species exhibit thick Z-lines. So, unlike other contractile proteins, the multiple forms of alpha-actinin do not reflect the distinction between fast- and slow-twitch muscles.
Source: The Journal of Cell Biology
Authors: F H Schachat, A C Canine, M M Briggs, M C Reedy
Institution: Duke Medical Center
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W2028082715