Linked Life Data

4020869

Source:http://linkedlifedata.com/resource/pubmed/id/4020869

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1985-9-20
pubmed:abstractText
We have sequenced 11 representative mutations of the unc-54 myosin heavy chain gene of Caenorhabditis elegans that affect the synthesis, assembly or enzymatic activity of the encoded myosin heavy chain. Six of the sequenced unc-54 mutations cause premature termination of protein synthesis. Four mutations (e1092, e1115, e1213, e1328) were ochre mutations, one mutation (e903) was a frameshift, which caused premature termination at a nearby UGA terminator, and one mutation (e190) was a deletion that altered the reading frame and caused termination at an ochre codon. Two mutations (e675 and s291) were inphase deletions, which resulted in a shortened myosin rod segment. These aberrant myosins fail to assemble into normal thick filaments. The sequence alterations of the missense mutations (e1152, s74, s95) indicated amino acid residues that are critical for myosin function. The mutation e1152 causes the production of a myosin heavy chain that fails to assemble into thick filaments. It had two adjacent amino acid substitutions at the extreme amino terminus of the rod, indicating a role for subfragment-2 in thick filament assembly. Mutants homozygous for s74 or s95 are very slow-moving, although they make myosin heavy chains that assemble normally. The encoded amino acid substitutions of s95 and s74 are in the 23 X 10(3) Mr and 50 X 10(3) Mr domains of the myosin head, flanking the ATP binding site. The sequenced mutations are distributed throughout the gene in the order predicted from genetic fine-structure mapping experiments. Seven of eight point mutations isolated following ethylmethane sulphonate mutagenesis were G X C to A X T transitions. A single X-ray-induced allele proved to be a deletion of two adjacent thymidine residues. The three deletion mutations were found in a region of the myosin rod with numerous direct and inverted nucleotide sequence repeats, but their origin cannot be accounted for by homologous recombination. Instead, a comparison of the deletion junctions suggests that the deletions arose by a site-specific mechanism.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
183
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
543-51
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
Sequence analysis of mutations that affect the synthesis, assembly and enzymatic activity of the unc-54 myosin heavy chain of Caenorhabditis elegans.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't