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Mutations in beta-spectrin disrupt axon outgrowth and sarcomere structure.

ABSTRACT: beta-Spectrin is a major component of the membrane skeleton, a structure found at the plasma membrane of most animal cells. beta-Spectrin and the membrane skeleton have been proposed to stabilize cell membranes, generate cell polarity, or localize specific membrane proteins. We demonstrate that the Caenorhabditis elegans homologue of beta-spectrin is encoded by the unc-70 gene. unc-70 null mutants develop slowly, and the adults are paralyzed and dumpy. However, the membrane integrity is not impaired in unc-70 animals, nor is cell polarity affected. Thus, beta-spectrin is not essential for general membrane integrity or for cell polarity. However, beta-spectrin is required for a subset of processes at cell membranes. In neurons, the loss of beta-spectrin leads to abnormal axon outgrowth. In muscles, a loss of beta-spectrin leads to disorganization of the myofilament lattice, discontinuities in the dense bodies, and a reduction or loss of the sarcoplasmic reticulum. These defects are consistent with beta-spectrin function in anchoring proteins at cell membranes.

SUBMITTER: Hammarlund M

PROVIDER: S-EPMC2174563 | biostudies-literature | 2000 May

REPOSITORIES: biostudies-literature

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Mutations in beta-spectrin disrupt axon outgrowth and sarcomere structure.

Hammarlund M M Davis W S WS Jorgensen E M EM

The Journal of cell biology 20000501 4

beta-Spectrin is a major component of the membrane skeleton, a structure found at the plasma membrane of most animal cells. beta-Spectrin and the membrane skeleton have been proposed to stabilize cell membranes, generate cell polarity, or localize specific membrane proteins. We demonstrate that the Caenorhabditis elegans homologue of beta-spectrin is encoded by the unc-70 gene. unc-70 null mutants develop slowly, and the adults are paralyzed and dumpy. However, the membrane integrity is not impa ...[more]

PMID: 10811832

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Mutations in beta-spectrin disrupt axon outgrowth and sarcomere structure.

Publications

Mutations in beta-spectrin disrupt axon outgrowth and sarcomere structure.

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