TY - JOUR
T1 - Cloning of mouse BMAL2 and its daily expression profile in the suprachiasmatic nucleus
T2 - A remarkable acceleration of Bmal2 sequence divergence after Bmal gene duplication
AU - Okano, Toshiyuki
AU - Sasaki, Momoko
AU - Fukada, Yoshitaka
N1 - Funding Information:
We thank Dr Daisuke Kojima for help in constructing phylogenetic tree, Dr Kimiko Shimizu for technical advice and Takaoki Kasahara and Tsuyoshi Hirota for technical assistance. This work was supported in part by Grants-in-aid from the Japanese Ministry of Education, Culture, Sports, Science and Technology.
PY - 2001/3/9
Y1 - 2001/3/9
N2 - Brain-Muscle-Arnt-Like-protein 2 (BMAL2; Arnt4) (aryl hydrocarbon receptor nuclear translocator) is a recently identified basic Helix-Loop-Helix-Per-Arnt-Sim (bHLH-PAS) transcription factor, which contributes to a positive regulation of autoregulatory feedback loop in vertebrate circadian clock systems. In this study, we cloned cDNAs encoding mouse and rat BMAL2 (mBMAL2 and rBMAL2) from mouse midbrain and rat-1 fibroblast cells, respectively. A phylogenetic analysis strongly suggested that vertebrate Bmal1 and Bmal2 genes were generated by a single gene duplication of an ancestral Bmal gene, a vertebrate ortholog of dCyc gene, and that 'BMAL2's putatively termed so far are orthologous. Interestingly, BMAL2 proteins have diverged about 20-fold more rapidly than BMAL1 proteins after the duplication, suggesting an as-yet-unidentified function conserved in BMAL1 but not in BMAL2. mBmal2 mRNA was constitutively expressed throughout the day under light-dark cycle in the mouse hypothalamus containing suprachiasmatic nucleus, the site of the central circadian oscillator in mammals.
AB - Brain-Muscle-Arnt-Like-protein 2 (BMAL2; Arnt4) (aryl hydrocarbon receptor nuclear translocator) is a recently identified basic Helix-Loop-Helix-Per-Arnt-Sim (bHLH-PAS) transcription factor, which contributes to a positive regulation of autoregulatory feedback loop in vertebrate circadian clock systems. In this study, we cloned cDNAs encoding mouse and rat BMAL2 (mBMAL2 and rBMAL2) from mouse midbrain and rat-1 fibroblast cells, respectively. A phylogenetic analysis strongly suggested that vertebrate Bmal1 and Bmal2 genes were generated by a single gene duplication of an ancestral Bmal gene, a vertebrate ortholog of dCyc gene, and that 'BMAL2's putatively termed so far are orthologous. Interestingly, BMAL2 proteins have diverged about 20-fold more rapidly than BMAL1 proteins after the duplication, suggesting an as-yet-unidentified function conserved in BMAL1 but not in BMAL2. mBmal2 mRNA was constitutively expressed throughout the day under light-dark cycle in the mouse hypothalamus containing suprachiasmatic nucleus, the site of the central circadian oscillator in mammals.
KW - BMAL
KW - Circadian rhythm
KW - Gene duplication
KW - Mouse
KW - Rat
KW - Suprachiasmatic nucleus
KW - bHLH-PAS
UR - http://www.scopus.com/inward/record.url?scp=0035831350&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0035831350&partnerID=8YFLogxK
U2 - 10.1016/S0304-3940(01)01581-6
DO - 10.1016/S0304-3940(01)01581-6
M3 - Article
C2 - 11207387
AN - SCOPUS:0035831350
VL - 300
SP - 111
EP - 114
JO - Neuroscience Letters
JF - Neuroscience Letters
SN - 0304-3940
IS - 2
ER -