TY - JOUR
T1 - An evolutionary hotspot defines functional differences between CRYPTOCHROMES
AU - Rosensweig, Clark
AU - Reynolds, Kimberly A.
AU - Gao, Peng
AU - Laothamatas, Isara
AU - Shan, Yongli
AU - Ranganathan, Rama
AU - Takahashi, Joseph S.
AU - Green, Carla B.
N1 - Funding Information:
We thank Andrew C. Liu and Hiroki Ueda for the generous gift of the Cry1−/−/Cry2−/− mouse embryonic fibroblasts and the Cry1 rescue vector. Research was supported by NIH grants (F31 NS089241 and T32 HL007909 to C.R.; R01 GM090247, R01 GM111387 and R01 GM112991 to C.B.G.; K.A.R. was supported by the Green Center for Systems Biology. J.S.T. is an Investigator in the Howard Hughes Medical Institute. R.R. acknowledges support from the NIH (RO1GM123456), the Robert A. Welch Foundation (I-1366), and the Lyda Hill Endowment for Systems Biology.
Publisher Copyright:
© 2018 The Author(s).
PY - 2018/12/1
Y1 - 2018/12/1
N2 - Mammalian circadian clocks are driven by a transcription/translation feedback loop composed of positive regulators (CLOCK/BMAL1) and repressors (CRYPTOCHROME 1/2 (CRY1/2) and PER1/2). To understand the structural principles of regulation, we used evolutionary sequence analysis to identify co-evolving residues within the CRY/PHL protein family. Here we report the identification of an ancestral secondary cofactor-binding pocket as an interface in repressive CRYs, mediating regulation through direct interaction with CLOCK and BMAL1. Mutations weakening binding between CLOCK/BMAL1 and CRY1 lead to acceleration of the clock, suggesting that subtle sequence divergences at this site can modulate clock function. Divergence between CRY1 and CRY2 at this site results in distinct periodic output. Weaker interactions between CRY2 and CLOCK/BMAL1 at this pocket are strengthened by co-expression of PER2, suggesting that PER expression limits the length of the repressive phase in CRY2-driven rhythms. Overall, this work provides a model for the mechanism and evolutionary variation of clock regulatory mechanisms.
AB - Mammalian circadian clocks are driven by a transcription/translation feedback loop composed of positive regulators (CLOCK/BMAL1) and repressors (CRYPTOCHROME 1/2 (CRY1/2) and PER1/2). To understand the structural principles of regulation, we used evolutionary sequence analysis to identify co-evolving residues within the CRY/PHL protein family. Here we report the identification of an ancestral secondary cofactor-binding pocket as an interface in repressive CRYs, mediating regulation through direct interaction with CLOCK and BMAL1. Mutations weakening binding between CLOCK/BMAL1 and CRY1 lead to acceleration of the clock, suggesting that subtle sequence divergences at this site can modulate clock function. Divergence between CRY1 and CRY2 at this site results in distinct periodic output. Weaker interactions between CRY2 and CLOCK/BMAL1 at this pocket are strengthened by co-expression of PER2, suggesting that PER expression limits the length of the repressive phase in CRY2-driven rhythms. Overall, this work provides a model for the mechanism and evolutionary variation of clock regulatory mechanisms.
UR - http://www.scopus.com/inward/record.url?scp=85044203683&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85044203683&partnerID=8YFLogxK
U2 - 10.1038/s41467-018-03503-6
DO - 10.1038/s41467-018-03503-6
M3 - Article
C2 - 29556064
AN - SCOPUS:85044203683
VL - 9
JO - Nature Communications
JF - Nature Communications
SN - 2041-1723
IS - 1
M1 - 1138
ER -