Activity of the circadian transcription factor White Collar Complex is modulated by phosphorylation of SP-motifs.
Posttranslational modifications, particularly phosphorylation, regulate activity, stability and localization of proteins in circadian clocks, thereby contributing to a stable oscillation with a period of approximately 24h. The White Collar Complex (WCC) is the central transcription factor of the circadian clock of Neurospora crassa. Its activity is regulated in a circadian manner by rhythmic phosphorylation, mediated by the clock protein Frequency (FRQ). Here we present purification of TAP-tagged WCC and identification of novel phosphorylation sites of WC-1 and WC-2, all of which appear to be proline directed. Exchange of a single WC-2 serine residue (S433) to alanine or aspartate affects WCC-dependent transcription and circadian period, suggesting an important role of WC-2 S433 phosphorylation for WCC activity and circadian timing.
University of Heidelberg Biochemistry Center, Heidelberg, Germany.
Gencer
G
Sancar
Cigdem
C
Sancar
Michael
M
Brunner
Tobias
T
Schafmeier
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001483:Base Sequence; D002940:Circadian Rhythm / Q000235:genetics / Q000502:physiology*; D017931:DNA Primers / Q000235:genetics; D004271:DNA, Fungal / Q000235:genetics; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009492:Neurospora crassa / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D012694:Serine / Q000737:chemistry; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D017931:DNA Primers; D004271:DNA, Fungal; D004268:DNA-Binding Proteins; C087405:FRQ protein, Neurospora crassa; D005656:Fungal Proteins; D014157:Transcription Factors; C105589:wc-1 protein, Neurospora crassa; C103772:white collar 2 protein, Neurospora; D012694:Serine