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PubMed · 8349030

Thyrotropin regulates thyroglobulin mRNA splicing and differential processing.

P N Graves·T F Davies
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Abstract

Rat thyroid tissue and cultured rat thyrocyte lines contain two thyroglobulin (Tg) mRNAs: a 9 kb rTg-1 mRNA encoding the 330, kDa Tg monomer and a recently described 0.95 kb rTg-2 mRNA. These transcripts have identical 5' coding sequences (641 nucleotides); however, the 3' end of rTg-2 is comprised of coding and non-coding sequences not present in rTg-1. To determine if a single Tg gene encoded both mRNA species, a genomic clone was isolated which spanned the full-length rTg-2 cDNA sequence. The promoter sequence and restriction map were the same as for the previously characterized rTg-1 gene, indicating that rTg-1 and rTg-2 mRNAs are splicing variants derived from the same Tg gene. The unique 3' end of rTg-2 mRNA comprised a single exon which was intronic with respect to rTg-1 mRNA formation. The level of rTg-2 in cultured rat thyrocytes was more sensitive to thyrotropin (TSH) regulation than was rTg-1. rTg-2 mRNA was rapidly (and reversibly) depleted to nearly undetectable levels after TSH removal, unlike rTg-1. Conversely, TSH rapidly restored control levels of rTg-2 mRNA in such depleted cells. The data thus support a model of TSH-induced splicing and regulation of the two Tg mRNAs in the rat.

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Amino Acid SequenceAnimalsBase SequenceCell LineCloning, MolecularGene Expression RegulationGenesMolecular Sequence DataPolymerase Chain ReactionPromoter Regions, GeneticRNA Processing, Post-TranscriptionalRNA SplicingRNA, MessengerRatsRestriction MappingThyroglobulinThyroid GlandThyrotropinComparative StudyJournal ArticleResearch Support, U.S. Gov't, P.H.S.

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P N Graves, T F Davies. 1993. Thyrotropin regulates thyroglobulin mRNA splicing and differential processing.. https://doi.org/10.1016/0303-7207(93)90126-5

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