Structural organization and chromosomal localization of the human type II deiodinase gene.
OBJECTIVE
The selenoenzyme type 2 iodothyronine 5' deiodinase (DII) catalyzes the conversion of thyroxine into its active form tri-iodothyronine (T3), modulating thyroid hormone homeostasis in a local, tissue-specific manner. The amphibian, rodent and human cDNAs encoding this enzyme have been recently cloned and expressed. At present, little information regarding the genomic structure of mammalian DII is available.


METHODS
The complete structure, including intron-exon junctions, of the human DII (hDII) gene was obtained by long PCR and rapid amplification of cDNA ends (RACE). Chromosomal assignment of the hDII gene was performed by fluorescence in situ hybridization using a highly specific probe.


CONCLUSIONS
Our data demonstrated that hDII is a single copy gene located on chromosome 14, position 14q24.3. The gene spans over 15 kb, and the 7 kb transcript is encoded by three exons of 149 bp, 273 bp and 6.6 kb separated respectively by two 274 bp and 7.4 kb introns. A restriction map of the hDII gene is also reported. These data will help in further studies of the role of DII in the maintenance of peripheral thyroid hormone homeostasis.
Celi
F S
FS
I Cattedra di Endocrinologia, Dipartimento di Medicina Sperimentale e Patologia, Università degli Studi di Roma La Sapienza, Roma, Italy. fsceli@axrma.uniroma1.it
Canettieri
G
G
Mentuccia
D
D
Proietti-Pannunzi
L
L
Fumarola
A
A
Sibilla
R
R
Predazzi
V
V
Ferraro
M
M
Andreoli
M
M
Centanni
M
M
D017398:Alternative Splicing; D001483:Base Sequence; D002874:Chromosome Mapping; D002883:Chromosomes, Human, Pair 14; D018076:DNA, Complementary / Q000737:chemistry*; D005091:Exons; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007438:Introns; D007453:Iodide Peroxidase / Q000235:genetics*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics; D015183:Restriction Mapping; D017385:Sequence Homology
D018076:DNA, Complementary; D012333:RNA, Messenger; D007453:Iodide Peroxidase