S. Song et al., Biochemical and molecular biological evidence for the presence of type II iodothyronine deiodinase in mouse mammary gland, MOL C ENDOC, 160(1-2), 2000, pp. 173-181
In the present study we have obtained several lines of evidence indicating
the presence of type II iodothyronine deiodinase (DII) in the mouse mammary
gland. 5'-deiodinase activity in the mammary gland has an apparent K-m val
ue of 4.4 nM for T-4 and is inhibited by aurothioglucose but not by propylt
hiouracil. These characteristics are similar to those of DII in other tissu
es. We cloned a 1.4-kb cDNA, which contains the entire mouse DII coding reg
ion and has high homology with the rat DII cDNA, from the mammary gland and
brain. Northern blot analysis showed the presence of 7.9 kb DII mRNA in th
e mammary gland and brain. The levels of DII activity and mRNA in lactating
gland were significantly lower than those in virgin and pregnant glands, s
uggesting that DII is regulated at the pretranslational level. In addition,
we found the low level of DII enzyme activity and transcript in various ot
her mouse tissues. Published by Elsevier Science Ireland Ltd.