6of7

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Crystal structure of the CRY1-PER2 complexCrystal structure of the CRY1-PER2 complex

Structural highlights

6of7 is a 2 chain structure with sequence from Homo sapiens and Mus musculus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 3.11Å
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

CRY1_MOUSE Blue light-dependent regulator of the circadian feedback loop. Inhibits CLOCK|NPAS2-ARNTL E box-mediated transcription. Acts, in conjunction with CRY2, in maintaining period length and circadian rhythmicity. Has no photolyase activity. Capable of translocating circadian clock core proteins such as PER proteins to the nucleus. May inhibit CLOCK|NPAS2-ARNTL transcriptional activity through stabilizing the unphosphorylated form of ARNTL.[1] [2] [3]

Publication Abstract from PubMed

Mammalian circadian rhythms are generated by a transcription-based feedback loop in which CLOCK:BMAL1 drives transcription of its repressors (PER1/2, CRY1/2), which ultimately interact with CLOCK:BMAL1 to close the feedback loop with ~24 hr periodicity. Here we pinpoint a key difference between CRY1 and CRY2 that underlies their differential strengths as transcriptional repressors. Both cryptochromes bind the BMAL1 transactivation domain similarly to sequester it from coactivators and repress CLOCK:BMAL1 activity. However, we find that CRY1 is recruited with much higher affinity to the PAS domain core of CLOCK:BMAL1, allowing it to serve as a stronger repressor that lengthens circadian period. We discovered a dynamic serine-rich loop adjacent to the secondary pocket in the photolyase homology region (PHR) domain that regulates differential binding of cryptochromes to the PAS domain core of CLOCK:BMAL1. Notably, binding of the co-repressor PER2 remodels the serine loop of CRY2, making it more CRY1-like and enhancing its affinity for CLOCK:BMAL1.

Dynamics at the serine loop underlie differential affinity of cryptochromes for CLOCK:BMAL1 to control circadian timing.,Fribourgh JL, Srivastava A, Sandate CR, Michael AK, Hsu PL, Rakers C, Nguyen LT, Torgrimson MR, Parico GCG, Tripathi S, Zheng N, Lander GC, Hirota T, Tama F, Partch CL Elife. 2020 Feb 26;9. pii: 55275. doi: 10.7554/eLife.55275. PMID:32101164[4]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. Kume K, Zylka MJ, Sriram S, Shearman LP, Weaver DR, Jin X, Maywood ES, Hastings MH, Reppert SM. mCRY1 and mCRY2 are essential components of the negative limb of the circadian clock feedback loop. Cell. 1999 Jul 23;98(2):193-205. PMID:10428031
  2. Kondratov RV, Kondratova AA, Lee C, Gorbacheva VY, Chernov MV, Antoch MP. Post-translational regulation of circadian transcriptional CLOCK(NPAS2)/BMAL1 complex by CRYPTOCHROMES. Cell Cycle. 2006 Apr;5(8):890-5. Epub 2006 Apr 17. PMID:16628007
  3. Chaves I, Yagita K, Barnhoorn S, Okamura H, van der Horst GT, Tamanini F. Functional evolution of the photolyase/cryptochrome protein family: importance of the C terminus of mammalian CRY1 for circadian core oscillator performance. Mol Cell Biol. 2006 Mar;26(5):1743-53. PMID:16478995 doi:10.1128/MCB.26.5.1743-1753.2006
  4. Fribourgh JL, Srivastava A, Sandate CR, Michael AK, Hsu PL, Rakers C, Nguyen LT, Torgrimson MR, Parico GCG, Tripathi S, Zheng N, Lander GC, Hirota T, Tama F, Partch CL. Dynamics at the serine loop underlie differential affinity of cryptochromes for CLOCK:BMAL1 to control circadian timing. Elife. 2020 Feb 26;9. pii: 55275. doi: 10.7554/eLife.55275. PMID:32101164 doi:http://dx.doi.org/10.7554/eLife.55275

6of7, resolution 3.11Å

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