DISTINCT LOCATION AND PREVALENCE OF ALPHA-CATENINS, BETA-CATENINS ANDGAMMA-CATENIN PLAKOGLOBIN IN DEVELOPING AND DENERVATED SKELETAL-MUSCLE/

We studied the distribution of alpha-catenin, beta-catenin and gamma-c atenin/plakoglobin in developing, adult and denervated mouse skeletal muscle. During primary myogenesis, all three catenins present a subsar colemmal distribution within primary myotubes. During secondary myogen esis they accumulate at myotube-myotube contacts. In contrast to the o ther catenins, gamma-catenin is strongly expressed in the sarcoplasm, In adult muscle, all three catenins are localized on the presynaptic e lements of the neuromuscular junction. In denervated muscles, alpha- a nd beta-catenins are upregulated like N- and M-cadherin, while the lev els of gamma-catenin/plakoglobin remain unchanged. The developmental c hanges in localization and regulation of alpha- and beta-catenins in m uscle compared to gamma-catenin/plakoglobin are suggestive of a privil eged association of alpha- and beta-catenins with N- and M-cadherins, while gamma-catenin/plakoglobin appears to be expressed quite independ ently and must assume a different role during myogenesis.