Characterization of Inhibitor of Growth 2 tumor suppressor in Alligator mississippiensis, its conservation in Archosauria, and response to thyroid stimulating hormone.
Inhibitor of growth 2 (ING2) belongs to a family of tumor suppressors that are important regulators of a wide range of cellular processes including proliferation, apoptosis, and DNA repair. ING family members are found in yeast, plants, invertebrates and many vertebrate species. However, to date, ING has not been characterized in reptiles. Herein we describe the isolation of expressed ING2 sequence in the American alligator, Alligator mississippiensis, and compare this sequence with that isolated in the chicken. We identify features that are unique to these two representatives of the Archosaurs including conservation of specific amino acid residues and the absence of an adenylate residue in the 5' end of the nucleotide sequence relative to frogs and mammals. The latter feature results in an alteration of the coding potential leading to distinctive N-termini. Injection of juvenile alligators with thyroid stimulating hormone (TSH), which increases endogenous thyroid hormones, results in the modulation of ING2 transcript levels. Quantitative real time polymerase chain reaction analyses revealed a reduction in the steady-state levels of ING2 mRNA in the phallus/cliterophallus, lung, and liver by 48 h after TSH injection. ING2 expression in the thyroid gland, gonad, and heart was unaffected by TSH treatment. These data indicate that control of ING2 expression by the thyroid axis may be conserved among species and is tissue-dependent.
Helbing
Caren C
CC
Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada. chelbing@uvic.ca
Crump
Kate
K
Bailey
Carmen M
CM
Kohno
Satomi
S
Veldhoen
Nik
N
Song
Yue
Y
Bryan
Teresa
T
Bermudez
Dieldrich S
DS
Ausió
Juan
J
Guillette
Louis J
LJ
D000489:Alligators and Crocodiles / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013972:Thyrotropin / Q000494:pharmacology*; D013997:Time Factors; D025521:Tumor Suppressor Proteins / Q000235:genetics*; D014714:Vertebrates / Q000145:classification / Q000235:genetics
D018076:DNA, Complementary; D025521:Tumor Suppressor Proteins; D013972:Thyrotropin