title: A role for casein kinase 2 in the mechanism underlying circadian temperature compensation.
abstract: Temperature compensation of circadian clocks is an unsolved problem with relevance to the general phenomenon of biological compensation. We identify casein kinase 2 (CK2) as a key regulator of temperature compensation of the Neurospora clock by determining that two long-standing clock mutants, chrono and period-3, displaying distinctive alterations in compensation encode the beta1 and alpha subunits of CK2, respectively. Reducing the dose of these subunits, particularly beta1, significantly alters temperature compensation without altering the enzyme's Q(10). By contrast, other kinases and phosphatases implicated in clock function do not play appreciable roles in temperature compensation. CK2 exerts its effects on the clock by directly phosphorylating FREQUENCY (FRQ), and this phosphorylation is compromised in CK2 hypomorphs. Finally, mutation of certain putative CK2 phosphosites on FRQ, shown to be phosphorylated in vivo, predictably alters temperature compensation profiles effectively phenocopying CK2 mutants.
authors.affiliation: Department of Genetics, Dartmouth Medical School, Hanover, NH 03755, USA.
authors.forename: Arun
authors.initials: A
authors.lastname: Mehra
authors.forename: Mi
authors.initials: M
authors.lastname: Shi
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Baker
authors.forename: Hildur V
authors.initials: HV
authors.lastname: Colot
authors.forename: Jennifer J
authors.initials: JJ
authors.lastname: Loros
authors.forename: Jay C
authors.initials: JC
authors.lastname: Dunlap
mesh_terms: D047390:Casein Kinase II / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D002940:Circadian Rhythm; D018628:Gene Dosage; D009154:Mutation; D009492:Neurospora crassa / Q000201:enzymology* / Q000502:physiology*; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D010770:Phosphotransferases / Q000378:metabolism; D021122:Protein Subunits / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D013696:Temperature
chemical_list: D021122:Protein Subunits; D010770:Phosphotransferases; D047390:Casein Kinase II; D010744:Phosphoric Monoester Hydrolases