[
Genes Dev,
2002]
The CM domain is a cysteine-rich DNA-binding motif first recognized in proteins encoded by the Drosophila set determination gene doublesex (Erdman and Burtis 1993; Zhu et al. 2000). As the name doublesex (dsx) suggests, this gene has functions in both sexes: Its transcripts undergo sex-specific alternative splicing, so that it can encode either a male-specific isoform, DSX(M), or a female-specific isoform, DSX(F) (Baker and Wolfner 1988; Burtis and Baker 1989). These proteins have the same N-terminal DNA-binding domain, but different C termini that confer different regulatory properties on the two forms. The expression of DSX(M) directs male development, and the expression of DSX(F) directs female development, throughout most of the somatic tissues of the fruit fly.
[
Worm,
2016]
Locomotion of C. elegans requires coordinated, efficient transmission of forces generated on the molecular scale by myosin and actin filaments in myocytes to dense bodies and the hypodermis and cuticle enveloping body wall muscles. The complex organization of the acto-myosin scaffold with its accessory proteins provides a fine-tuned machinery regulated by effectors that guarantees that sarcomere units undergo controlled, reversible cycles of contraction and relaxation. Actin filaments in sarcomeres dynamically undergo polymerization and depolymerization. In a recent study, the actin-binding protein DBN-1, the C. elegans ortholog of human drebrin and drebrin-like proteins, was discovered to stabilize actin in muscle cells. DBN-1 reversibly changes location between actin filaments and myosin-rich regions during muscle contraction. Mutations in DBN-1 result in mislocalization of other actin-binding proteins. Here we discuss implications of this finding for the regulation of sarcomere actin stability and the organization of other actin-binding proteins.