Disease relevance of Mlc1

• A recombinant lambda-phage DNA clone containing Drosophila melanogaster sequences encoding the gene for myosin light chain (MLC) two has been isolated from a library of randomly sheared DNA [1].

High impact information on Mlc1

• Myosin light chain-activating phosphorylation sites are required for oogenesis in Drosophila [2].
• The Drosophila MLC2 gene is located in region 99E1-3 on the right arm of chromosome 3, several bands removed from the site reported for the other myosin light chain gene at 98B [1].
• By sequence comparisons with an MLC-ALK cDNA clone and by S1 nuclease analyses, the pattern of introns and exons within the gene has been deduced [3].
• Developmental variations in the splicing pattern of transcripts from the Drosophila gene encoding myosin alkali light chain result in different carboxyl-terminal amino acid sequences [3].
• The genomic organization of a novel regulatory myosin light chain gene (MYL5) that maps to chromosome 4p16.3 and shows different patterns of expression between primates [4].

Biological context of Mlc1

• To distinguish the past action of evolutionary forces in introns known to have regulatory information, we examined nucleotide sequence variation at 991 sites in a random sample of 16 Drosophila melanogaster alleles of the gene encoding the myosin alkali light chain (Mlc1) [5].
• Although there is little evidence for pairwise linkage disequilibrium in the Mlc1 region, higher order disequilibrium does seem to be present in the 5' half of the portion of the gene that was examined [5].
• We show that this tissue-specific pattern of alternative splicing of the Mlc1 pre-mRNA is conserved in D. simulans, D. pseudoobscura, and D. virilis [6].
• Here we perform a phylogenetic analysis, inferring ancestral states wherever possible on a phylogeny of 29 alleles of Mlc1 from six species of Drosophila [7].
• We report here the identification and characterization of a gene (MYL5) that encodes a novel regulatory myosin light chain isoprotein and maps 700 kb from the human chromosome 4p telomere [4].

Anatomical context of Mlc1

• We have characterized the function of myosin light chain phosphatase, which down-regulates myosin activity, in Drosophila photoreceptor neurons [8].
• The rise in [Ca2+]i activates key signaling pathways that mediate cytoskeletal reorganization (through myosin-light-chain-dependent contraction) and the disassembly of VE-cadherin at the adherens junctions [9].
• Untreated T-lymphocytes contain phosphate in the serine-19 residue of the myosin light chain, and in a residue tentatively identified as serine-1944 in the myosin heavy chain [10].
• Original data indicating that treatment of human T-lymphocytes (Jurkat cell line) with phorbol 12-myristate 13-acetate results in phosphorylation of both the 20 kD myosin light chain as well as the 200 kD myosin heavy chain is presented [10].

Associations of Mlc1 with chemical compounds

• The 3' splice site that precedes exon 18 is unusually purine-rich, may form a stem-loop structure with the 5' splice site following exon 18, and is conserved relative to the splice site of an alternative exon of the Drosophila alkali myosin light chain gene [11].

Physical interactions of Mlc1

• We interpret these results as possibly caused either by effects on A1 myosin light chain binding or conformational changes within the subdomain 1 of actin, which contains the myosin binding site [12].

Regulatory relationships of Mlc1

• We demonstrate that the contractile ring protein anillin interacts directly with nonmuscle myosin II and that this interaction is regulated by myosin light chain phosphorylation [13].
• In addition, the 3' end of the stretchin-MLCK transcription unit expresses shorter transcripts that encode 86 to 165 kDa isoforms of stretchin-MLCK that are analogous to vertebrate Myosin light chain kinases [14].

References