MRLC, myosin II, MyoII, myosin regulatory light chain, RLC
Gene model reviewed during 5.49
Low-frequency RNA-Seq exon junction(s) not annotated.
Annotated transcripts do not represent all supported alternative splices within 5' UTR.
Gene model reviewed during 5.55
1.2 (northern blot)
174 (aa); 20 (kD)
Myosin is a hexamer of 2 heavy chains and 4 light chains.
Phosphorylation plays a central role in myosin regulation.
Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\sqh using the Feature Mapper tool.
The distribution of monophosphorylated squ (designated Sqh1P) and diphosphorylated sqh (designated Sqh2P) were compared. In embryos, Sqh1P is fairly ubiquitously expressed and has a pattern that is indistinguishable from total sqh and zip. In cellularizing embryos, staining is observed at the leading edge of cleavage furrows. In gastrulating embryos, it is observed in the cytoplasm with enrichment near the basal membrane in dorsal and lateral cells with more apical enrichment in gastrulating cells. In stage 12 embryos, epithelial cells appear to be outlined. In the salivary gland Sqh1P is localized apically. In stage 14 embryos, high levels of Sqh1P are seen in the ventral nerve cord relative to the rest of the embryo and expression is also strong in the pharynx, foregut, hindgut and epidermis. Sqh2P is expressed in the invaginating stomodeum and proctodeum in stage 10 embryos. At stage 11, it is strongly expressed in the tracheal placodes and can still be observed in the proctodeal opening. In stage 12, Sqh2P is expressed in the invaginating tracheal metameres. At stage 13, it is expressed in the tracheal system as adjacent metemeres are fusing. It is also expressed strongly in epidermal cells that line the segmental boundary but not in intersegmental epidermal cells. Strong localization is seen at stage 14 in the dorsal pouch.
GBrowse - Visual display of RNA-Seq signalsView Dmel\sqh in GBrowse 2
Please Note This section lists cDNAs and ESTs that fall within the genomic extent of the gene model, which may include cDNAs and ESTs of genes within introns, or of overlapping genes. Please see GBrowse for alignment of the cDNAs and ESTs to the gene model.
For each fully sequenced cDNA the DGRC maintains various forms of the cDNA (e.g tagged or untagged) in several different host vectors for subsequent cloning and expression in Drosophila and Drosophila cell lines.
Inhibition of sqh by injection of Y-27632 in embryos results in cuticle shaping defects.
dsRNA directed against this gene causes defects in cytokinesis when tested in an RNAi screen in S2 cells.
Pharmacological and genetic analyses show that sqh is not necessary for the first phase of cellularization in embryos, but is needed for basal closure of the cellularization furrows.
Mutant analysis indicates that phosphorylation sites of sqh protein are essential for its function in vivo.
sqh mutant phenotypes are chiefly caused by sequestration of myosin into inactive aggregates.
Phosphorylation at the putative target of myosin light chain kinase is essential for the in vivo activity of the sqh product. Altered sqh lacking all three putative targets of protein kinase C and p34/cdc2 kinase still functions adequately during cytokinesis, but not wing formation.
Supply of sqh by the maternal germ line is required normal embryonic development, specifically for both dumping, rapid phase of cytoplasmic transport, and axial expansion of the cloud of cleavage nuclei during the first 6 cycles of nuclear division.
A weak allele is 100% lethal due to failure of larval cytokinesis, insertions of a heat shock inducible sqh cDNA rescue larvae to adulthood.
sqh encodes the regulatory light chain of the nonmuscle myosin.
The structural gene for cytoplasmic myosin light chain (Chang, Edwards and Kiehart, Karess, Kulkarni and Aguilera, 1991).