TY - JOUR
T1 - Dictyostelium discoideum myosin
T2 - isolation and characterization of cDNAs encoding the regulatory light chain.
AU - Tafuri, S. R.
AU - Rushforth, A. M.
AU - Kuczmarski, E. R.
AU - Chisholm, R. L.
N1 - Copyright:
This record is sourced from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
PY - 1989/7
Y1 - 1989/7
N2 - Phosphorylation of the regulatory light chains (RMLC) of nonmuscle myosin can increase the actin-activated ATPase activity and filament formation. Little is known about these regulatory mechanisms and how the RMLC are involved in ATP hydrolysis. To better characterize the nonmuscle RMLC, we isolated cDNAs encoding the Dictyostelium RMLC. Using an antibody specific for the RMLC, we screened a lambda gt11 expression library and obtained a 200-base-pair clone that encoded a portion of the RMLC. The remainder of the sequence was obtained from two clones identified by DNA hybridization, using the 200-base-pair cDNA. The composite RMLC cDNA was 645 nucleotides long. It contained 60 base pairs of 5' untranslated, 483 bases of coding, and 102 base pairs of 3' untranslated sequence. The amino acid sequence predicted an 18,300-dalton protein that shares 42% amino acid identity with Dictyostelium calmodulin and 30% identity with the chicken skeletal myosin RMLC. This sequence contained three regions that were similar to the E-F hand calcium-binding domains found in calmodulin, troponin C, and other myosin light chains. A sequence similar to the phosphorylation sequence found in chicken gizzard and skeletal myosin light chains was found at the amino terminus. Genomic Southern blot analysis suggested that the Dictyostelium genome contains a single gene encoding the RMLC. Analysis of RMLC expression patterns during Dictyostelium development indicated that accumulation of this mRNA increases just before aggregation and again during culmination. This pattern is similar to that obtained for the Dictyostelium essential myosin light chain and suggests that expression of the two light chains is coordinated during development.
AB - Phosphorylation of the regulatory light chains (RMLC) of nonmuscle myosin can increase the actin-activated ATPase activity and filament formation. Little is known about these regulatory mechanisms and how the RMLC are involved in ATP hydrolysis. To better characterize the nonmuscle RMLC, we isolated cDNAs encoding the Dictyostelium RMLC. Using an antibody specific for the RMLC, we screened a lambda gt11 expression library and obtained a 200-base-pair clone that encoded a portion of the RMLC. The remainder of the sequence was obtained from two clones identified by DNA hybridization, using the 200-base-pair cDNA. The composite RMLC cDNA was 645 nucleotides long. It contained 60 base pairs of 5' untranslated, 483 bases of coding, and 102 base pairs of 3' untranslated sequence. The amino acid sequence predicted an 18,300-dalton protein that shares 42% amino acid identity with Dictyostelium calmodulin and 30% identity with the chicken skeletal myosin RMLC. This sequence contained three regions that were similar to the E-F hand calcium-binding domains found in calmodulin, troponin C, and other myosin light chains. A sequence similar to the phosphorylation sequence found in chicken gizzard and skeletal myosin light chains was found at the amino terminus. Genomic Southern blot analysis suggested that the Dictyostelium genome contains a single gene encoding the RMLC. Analysis of RMLC expression patterns during Dictyostelium development indicated that accumulation of this mRNA increases just before aggregation and again during culmination. This pattern is similar to that obtained for the Dictyostelium essential myosin light chain and suggests that expression of the two light chains is coordinated during development.
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U2 - 10.1128/MCB.9.7.3073
DO - 10.1128/MCB.9.7.3073
M3 - Article
C2 - 2550795
AN - SCOPUS:0024694502
VL - 9
SP - 3073
EP - 3080
JO - Molecular and Cellular Biology
JF - Molecular and Cellular Biology
SN - 0270-7306
IS - 7
ER -