Linked Life Data

2628739

Source:http://linkedlifedata.com/resource/pubmed/id/2628739

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1990-4-25
pubmed:abstractText
The phenolic (5' position) and tyrosyl (5 position) ring deiodinases which catalyze the peripheral metabolism of thyroid hormones have proven difficult to purify and characterize biochemically. The present studies used Xenopus laevis oocytes as an in vivo translational assay system for detecting and quantitating mRNA for these enzymes. The injection of poly(A)+ RNA prepared from a human term placenta induced 5-deiodinase activity in oocytes. The expressed activity increased for up to 96 h after injection, was proportional to the amount of RNA injected, and manifested a Michaelis-Menten constant (Km) for T3 of 1.6 nM. In oocytes injected with poly(A)+ RNA prepared from rat liver, anterior pituitary gland, or brown adipose tissue, 5-deiodinase activity could not be demonstrated. The injection of poly(A)+ RNA from 15-day-old chick embryonic liver induced both 5'- and 5-deiodinase activity, with the 5'-deiodinase activity being sensitive to inhibition by 6-n-propyl-2-thiouracil. X. laevis oocytes can thus be induced to express either phenolic or tyrosyl ring deiodinase activity, or both, by the microinjection of poly(A)+ RNA prepared from selected tissues. These findings demonstrate that the types of deiodinase activity present in different organs represent tissue specific patterns of mRNA expression and strongly suggest that the enzymes responsible for types I and III deiodinase activity are encoded by different mRNAs.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0888-8809
pubmed:author
pubmed:issnType
Print
pubmed:volume
3
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2049-53
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Expression of phenolic and tyrosyl ring iodothyronine deiodinases in Xenopus laevis oocytes is dependent on the tissue source of injected poly(A)+ RNA.
pubmed:affiliation
Department of Medicine, Dartmouth Medical School, Hanover, New Hampshire 03756.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't