High impact information on mlc-1

• Removal of the pseudosubstrate sequence from members of the myosin light-chain kinase subfamily, including twitchin kinase, activates them but it is not known whether the pseudosubstrate sequence binds to the active site [1].
• The nonmuscle myosin regulatory light chain gene mlc-4 is required for cytokinesis, anterior-posterior polarity, and body morphology during Caenorhabditis elegans embryogenesis [2].
• We used the polymerase chain reaction to detect insertions of the transposon Tc1 into mlc-2, one of two Caenorhabditis elegans regulatory myosin light chain genes [3].
• We show that a regulatory myosin light chain normally becomes phosphorylated on the apical side of ingressing cells at a conserved site that can lead to myosin-filament formation and contraction of actomyosin networks and that this phosphorylation depends on Wnt signaling [4].
• It consists of multiple copies of both fibronectin III and immunoglobulin C2 domains and, near the C terminus, a protein kinase domain with greatest homology to the catalytic domains of myosin light chain kinases [5].

Biological context of mlc-1

• We determined the complete nucleotide sequences of both mlc-1 and mlc-2 [6].
• CONCLUSIONS: We conclude that Wnt signaling regulates C. elegans gastrulation through regulatory myosin light-chain phosphorylation, which results in the contraction of the apical surface of ingressing cells [4].
• The present report, describing the sequence and expression throughout development of the amphioxus gene for alkali myosin light chain (AmphiMLC-alk), thus fills a major gap in understanding the relation between gene duplication and increasing diversity of muscle-cell types [7].
• We inserted the cDNA encoding this 238-amino-acid (aa) jellyfish protein into an expression vector containing the rat myosin light-chain enhancer (MLC-GFP) to evaluate its ability to serve as a muscle-specific marker [8].

Anatomical context of mlc-1

• Four observations suggest that hermaphrodite-specific lethality of mlc-2(0) mutants results from insufficient expression of the X-linked mlc-1(+) gene in the pharynx [9].
• Functions of mlc-1 are redundant to those of mlc-2 in both body-wall and pharyngeal muscle. mlc-1(0) mutants are wild type, but mlc-1(0) mlc-2(0) double mutants arrest as incompletely elongated L1 larvae, having both pharyngeal and body-wall muscle defects [9].
• Recently, the presence of immunoglobulin folds of this type has been reported in some intracellular muscular proteins, namely in smooth muscle myosin light chain kinase, striated muscle C protein and titin, as well as in the nematode 600-kDa protein twitchin [10].

Associations of mlc-1 with chemical compounds

• Here we present evidence that RhoA, the guanine nucleotide-exchange factor ECT-2, and the Rho guanosine triphosphatase-activating protein CYK-4 modulate myosin light-chain activity to create a gradient of actomyosin, which establishes the anterior domain [11].

Other interactions of mlc-1

• Both mlc-1 and mlc-2 encode abundant mRNAs [6].

References