[Frontiers in Bioscience 6, d53-64, January 1, 2001]

CELLULAR AND MOLECULAR PROPERTIES OF ALPHA-DYSTROBREVIN IN SKELETAL MUSCLE

Rebecca E. Enigk and Margaret M. Maimone

Department of Cell and Developmental Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA

TABLE OF CONTENTS

1. Abstract
2. Introduction
3. Alpha-dystrobrevin, a dystrophin-related protein, is a component of the dystrophin glycoprotein complex
4. Cloning of alpha-dystrobrevin
4.1. Alpha-dystrobrevin gene structure
4.2. Alpha-dystrobrevin cDNAs generated by alternative splicing
5. Expression of alpha-dystrobrevin
5.1. Tissue expression
5.2. Developmental expression in muscle cell cultures
6. Properties of alpha-dystrobrevin in skeletal muscle
6.1. Subcellular localization
6.2. Protein-protein interactions
6.3. Phosphorylation
7. Potential functions of alpha-dystrobrevin in skeletal muscle
7.1. Muscular dystrophy in alpha-dystrobrevin deficient mice
7.2. Neuromuscular defects in alpha-dystrobrevin deficient mice
8. Perspectives
9. Acknowledgments
10. References

1. ABSTRACT

The dystrophin glycoprotein complex (DGC) is a large multisubunit complex located throughout the sarcolemma of striated muscle fibers. This complex is critical for maintaining the structural integrity of muscle fibers during muscle contraction and also provides a scaffold for signaling molecules. Defects in some components of the DGC, such as dystrophin and sarcoglycans, disrupt the complex and lead to muscular dystrophies. Alpha-dystrobrevin is a dystrophin-related component of the DGC that is localized to the cytoplasmic side of the sarcolemma. In skeletal muscle, alpha-dystrobrevin is also highly concentrated at the neuromuscular junction, a highly specialized region of the sarcolemma responsible for receiving motor nerve signals necessary for muscle contraction. Current evidence suggests that alpha-dystrobrevin plays an important role in signaling at the sarcolemma and in the maturation and maintenance of the postsynaptic apparatus at the neuromuscular junction. In this review, we summarize the currently known cellular and molecular properties of alpha-dystrobrevin in skeletal muscle and discuss its potential functions at both the sarcolemma and neuromuscular junction.