1 Ocak 2020 Dergi makalesi Açık Erişim

Gul, Seref; Aydin, Cihan; Ozcan, Onur; Gurkan, Berke; Surme, Saliha; Baris, Ibrahim; Kavakli, Ibrahim Halil

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{
  "DOI": "10.1074/jbc.RA120.014333", 
  "abstract": "Mammalian circadian clocks are driven by transcription/translation feedback loops composed of positive transcriptional activators (BMAL1 and CLOCK) and negative repressors (CRYPTOCHROMEs (CRYs) and PERIODs (PERs)). CRYs, in complex with PERs, bind to the BMAL1/CLOCK complex and repress E-box-driven transcription of clock-associated genes. There are two individual CRYs, with CRY1 exhibiting higher affinity to the BMAL1/CLOCK complex than CRY2. It is known that this differential binding is regulated by a dynamic serine-rich loop adjacent to the secondary pocket of both CRYs, but the underlying features controlling loop dynamics are not known. Here we report that allosteric regulation of the serine-rich loop is mediated by Arg-293 of CRY1, identified as a rare CRY1 SNP in the Ensembl and 1000 Genomes databases. The p.Arg293His CRY1 variant caused a shortened circadian period in a Cry1(-/-)Cry2(-/-) double knockout mouse embryonic fibroblast cell line. Moreover, the variant displayed reduced repressor activity on BMAL1/CLOCK driven transcription, which is explained by reduced affinity to BMAL1/CLOCK in the absence of PER2 compared with CRY1. Molecular dynamics simulations revealed that the p.Arg293His CRY1 variant altered a communication pathway between Arg-293 and the serine loop by reducing its dynamicity. Collectively, this study provides direct evidence that allosterism in CRY1 is critical for the regulation of circadian rhythm.", 
  "author": [
    {
      "family": "Gul", 
      "given": " Seref"
    }, 
    {
      "family": "Aydin", 
      "given": " Cihan"
    }, 
    {
      "family": "Ozcan", 
      "given": " Onur"
    }, 
    {
      "family": "Gurkan", 
      "given": " Berke"
    }, 
    {
      "family": "Surme", 
      "given": " Saliha"
    }, 
    {
      "family": "Baris", 
      "given": " Ibrahim"
    }, 
    {
      "family": "Kavakli", 
      "given": " Ibrahim Halil"
    }
  ], 
  "container_title": "JOURNAL OF BIOLOGICAL CHEMISTRY", 
  "id": "9225", 
  "issue": "50", 
  "issued": {
    "date-parts": [
      [
        2020, 
        1, 
        1
      ]
    ]
  }, 
  "page": "17187-17199", 
  "title": "The Arg-293 of Cryptochrome1 is responsible for the allosteric regulation of CLOCK-CRY1 binding in circadian rhythm", 
  "type": "article-journal", 
  "volume": "295"
}