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A PEST‐like element in FREQUENCY determines the length of the circadian period in Neurospora crassa
Author(s) -
Görl Margit,
Merrow Martha,
Huttner Benedikt,
Johnson Judy,
Roenneberg Till,
Brunner Michael
Publication year - 2001
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/20.24.7074
Subject(s) - neurospora crassa , biology , conidiation , neurospora , circadian clock , pest analysis , circadian rhythm , casein kinase 1 , period (music) , fungal protein , genetics , mutant , botany , microbiology and biotechnology , protein kinase a , gene , phosphorylation , endocrinology , physics , acoustics
FREQUENCY (FRQ) is a crucial element of the circadian clock in Neurospora crassa . In the course of a circadian day FRQ is successively phosphorylated and degraded. Here we report that two PEST‐like elements in FRQ, PEST‐1 and PEST‐2, are phosphorylated in vitro by recombinant CK‐1a and CK‐1b, two newly identified Neurospora homologs of casein kinase 1ϵ. CK‐1a is localized in the cytosol and the nuclei of Neurospora and it is in a complex with FRQ in vivo . Deletion of PEST‐1 results in hypophosphorylation of FRQ and causes significantly increased protein stability. A strain harboring the mutant frq ΔPEST‐1 gene shows no rhythmic conidiation. Despite the lack of overt rhythmicity, frq ΔPEST‐1 RNA and FRQΔPEST‐1 protein are rhythmically expressed and oscillate in constant darkness with a circadian period of 28 h. Thus, by deletion of PEST‐1 the circadian period is lengthened and overt rhythmicity is dissociated from molecular oscillations of clock components.