title: Interaction of circadian clock proteins CRY1 and PER2 is modulated by zinc binding and disulfide bond formation.
abstract: Period (PER) proteins are essential components of the mammalian circadian clock. They form complexes with cryptochromes (CRY), which negatively regulate CLOCK/BMAL1-dependent transactivation of clock and clock-controlled genes. To define the roles of mammalian CRY/PER complexes in the circadian clock, we have determined the crystal structure of a complex comprising the photolyase homology region of mouse CRY1 (mCRY1) and a C-terminal mouse PER2 (mPER2) fragment. mPER2 winds around the helical mCRY1 domain covering the binding sites of FBXL3 and CLOCK/BMAL1, but not the FAD binding pocket. Our structure revealed an unexpected zinc ion in one interface, which stabilizes mCRY1-mPER2 interactions in vivo. We provide evidence that mCRY1/mPER2 complex formation is modulated by an interplay of zinc binding and mCRY1 disulfide bond formation, which may be influenced by the redox state of the cell. Our studies may allow for the development of circadian and metabolic modulators.
authors.affiliation: Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried/Munich, Germany.
authors.forename: Ira
authors.initials: I
authors.lastname: Schmalen
authors.affiliation: Laboratory of Chronobiology, Charité Universitätsmedizin Berlin, Hessische Strasse 3-4, 10115 Berlin, Germany.
authors.forename: Silke
authors.initials: S
authors.lastname: Reischl
authors.affiliation: Laboratory of Chronobiology, Charité Universitätsmedizin Berlin, Hessische Strasse 3-4, 10115 Berlin, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Wallach
authors.affiliation: Laboratory of Chronobiology, Charité Universitätsmedizin Berlin, Hessische Strasse 3-4, 10115 Berlin, Germany.
authors.forename: Roman
authors.initials: R
authors.lastname: Klemz
authors.affiliation: Laboratory of Chronobiology, Charité Universitätsmedizin Berlin, Hessische Strasse 3-4, 10115 Berlin, Germany.
authors.forename: Astrid
authors.initials: A
authors.lastname: Grudziecki
authors.affiliation: Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried/Munich, Germany.
authors.forename: J Rajan
authors.initials: JR
authors.lastname: Prabu
authors.affiliation: Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried/Munich, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Benda
authors.affiliation: Laboratory of Chronobiology, Charité Universitätsmedizin Berlin, Hessische Strasse 3-4, 10115 Berlin, Germany. Electronic address: achim.kramer@charite.de.
authors.forename: Achim
authors.initials: A
authors.lastname: Kramer
authors.affiliation: Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried/Munich, Germany; Department of Physiological Chemistry, Butenandt Institute, Ludwig Maximilians University of Munich, Butenandtstrasse 5, 81377 Munich, Germany. Electronic address: evawolf1@uni-mainz.de.
authors.forename: Eva
authors.initials: E
authors.lastname: Wolf
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D056931:Cryptochromes / Q000737:chemistry* / Q000378:metabolism*; D018360:Crystallography, X-Ray; D044783:F-Box Proteins / Q000737:chemistry / Q000378:metabolism; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D056950:Period Circadian Proteins / Q000737:chemistry* / Q000378:metabolism*; D054730:Protein Interaction Domains and Motifs; D011994:Recombinant Proteins; D016415:Sequence Alignment; D015032:Zinc / Q000378:metabolism
chemical_list: C538964:Cry1 protein, mouse; D056931:Cryptochromes; D044783:F-Box Proteins; C519794:Fbxl3 protein, mouse; C513312:Per2 protein, mouse; D056950:Period Circadian Proteins; D011994:Recombinant Proteins; D015032:Zinc