Linked Life Data

6317873

Source:http://linkedlifedata.com/resource/pubmed/id/6317873

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1984-2-24
pubmed:abstractText
Evolutionary studies on the tubulin multigene families were initiated by nucleotide sequence analysis of cDNA clones complementary to sea urchin (Lytechinus pictus) testis alpha- and beta-tubulin cDNA clones (p beta 1, p beta 2, p beta e) demonstrated the existence of tubulin mRNA heterogeneity. p beta 2 and p beta 3 contain identical tubulin-coding regions and extremely similar 3' untranslated sequences, including a polyadenylation signal (AAUAAA). However, p beta 2 contains an additional region of 3' untranslated sequence which includes a second polyadenylation signal. These two sequences may be allelic, representing products of alternative transcription termination or processing pathways. p beta 1 and p beta 2 (or p beta 3) cDNAs almost certainly correspond to transcripts of distinct but evolutionarily related genes. Examination of the available coding portions showed that they differ only by a few silent nucleotide substitutions and the deletion/insertion of one codon; most of the differences are clustered within the last 15 3'-end codons. In contrast, their 3' untranslated sequences are considerably divergent. Nucleotide alignment in this region was feasible by considering specific point and segmental mutations, mainly T in equilibrium or formed from C transitions and small deletions/insertions associated with small direct repeats. The sea urchin alpha- and beta-tubulin cDNA and corresponding protein sequences were compared with previously described tubulin cDNA and protein sequences from other organisms. Both alpha and beta tubulins are very conserved proteins, evolving with a rate comparable to that of histones. Analysis of the nucleotide divergence of the coding cDNA regions showed that replacement sites have changed with a rate 20-175 times lower than that of the silent sites. Among the 177 codons compared between the sea urchin testis and chick brain beta-tubulin cDNAs, there are 7 conservative amino acid replacements and the deletion/insertion of two codons. Most of these changes are clustered near the C-terminus. The 161-amino acid portion of chick brain, rat and porcine alpha-tubulin sequences differs by 3 conservative amino acid replacements from the corresponding sea urchin testis alpha-tubulin sequence. The compared interspecies 3' untranslated sequences are very divergent.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0022-2844
pubmed:author
pubmed:issnType
Print
pubmed:volume
19
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
397-410
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1983
pubmed:articleTitle
Evolution of alpha q- and beta-tubulin genes as inferred by the nucleotide sequences of sea urchin cDNA clones.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.