Open AccesshnRNP K Supports High-Amplitude D Site-Binding Protein mRNA (Dbp mRNA) Oscillation To Sustain Circadian Rhythms
Author(s) -
Paul Kwangho Kwon,
Kyung-Ha Lee,
Ji Hyung Kim,
Sookil Tae,
Seokjin Ham,
YoungHun Jeong,
Sung Wook Kim,
Byung Ha Kang,
Hyo-Min Kim,
JungHyun Choi,
Hee Yi,
Hyun-Ok Ku,
Tae-Young Roh,
Chunghun Lim
Publication year - 2020
Publication title -
molecular and cellular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.14
H-Index - 327
eISSN - 1067-8824
pISSN - 0270-7306
DOI - 10.1128/mcb.00537-19
Subject(s) - biology , circadian rhythm , messenger rna , oscillation (cell signaling) , rhythm , microbiology and biotechnology , genetics , endocrinology , medicine , gene
Circadian gene expression is defined by the gene-specific phase and amplitude of daily oscillations in mRNA and protein levels. D site-binding protein mRNA ( Dbp mRNA) shows high-amplitude oscillation; however, the underlying mechanism remains elusive. Here, we demonstrate that heterogeneous nuclear ribonucleoprotein K (hnRNP K) is a key regulator that activates Dbp transcription via the poly(C) motif within its proximal promoter. Biochemical analyses identified hnRNP K as a specific protein that directly associates with the poly(C) motif in vitro Interestingly, we further confirmed the rhythmic binding of endogenous hnRNP K within the Dbp promoter through chromatin immunoprecipitation as well as the cycling expression of hnRNP K. Finally, knockdown of hnRNP K decreased mRNA oscillation in both Dbp and Dbp -dependent clock genes. Taken together, our results show rhythmic protein expression of hnRNP K and provide new insights into its function as a transcriptional amplifier of Dbp .