Linked Life Data

2422084

Source:http://linkedlifedata.com/resource/pubmed/id/2422084

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1986-6-16
pubmed:abstractText
Cytokeratin A (no. 8) is a cytoskeletal protein (Mr, approximately 53,000 in bovine cells) which is typical of all simple epithelia, is widespread in all cultured epithelial cells, and together with its partner cytokeratin D, is the first cytokeratin expressed during embryogenesis (synonyms for this protein are Endo A and TROMA-1 antigen). We isolated a clone (pKB8(1] from a pUC8 cDNA library prepared from poly(A)+-RNA of bovine bladder urothelium which contains the 3' nontranslated portion and the sequence coding for the carboxyterminal tail and almost the whole of the alpha-helical rod (369 amino acids). Northern-blot analysis showed that the mRNA coding for this cytokeratin is specifically synthesized in various epithelial tissues and in epithelial cell culture lines. The amino acid sequence of this cytokeratin, when compared with the sequences of other intermediate filament (IF) proteins, exhibits a high and specific homology with other cytokeratins of the basic (type II) subfamily; this homology is, however, restricted to the rod portion. The tail region, which is rich in hydroxy-amino acids (approximately 35%), is unique among the type-II cytokeratins in that it does not exhibit subdivision in three domains, specifically lacking the glycine-rich middle domain. Sequence comparison with a partial sequence of the corresponding cytokeratin of the amphibian species, Xenopus laevis, indicated high evolutionary conservation. The high sequence homology of bovine cytokeratin A with published sequences of human tissue polypeptide antigen (TPA), a soluble serum component used as tumor marker in clinical oncology, supports the view that TPA is a proteolytically solubilized fragment containing the rod portion of human cytokeratin no. 8. Our analysis of clone pKB8(1) made possible the first comparison of a simple epithelial cytokeratin with epidermal keratins and other IF proteins. This showed that, in some important molecular features, cytokeratin A (no. 8) differs drastically from the epidermal members of the same cytokeratin subfamily, probably reflecting different cellular functions of the tail region in stratified and simple epithelia.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0301-4681
pubmed:author
pubmed:issnType
Print
pubmed:volume
30
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
254-64
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
Cytokeratin expression in simple epithelia. II. cDNA cloning and sequence characteristics of bovine cytokeratin A (no. 8).
pubmed:publicationType
Journal Article, Comparative Study