biostudies-literaturePeng HZhejiang Provincial R&D ProgramNational Natural Science Foundation of ChinaZhejiang Provincial R&amp;D Program558https://www.ebi.ac.uk/biostudies/studies/S-EPMC9224670biostudies-literatureUnknown8(6)FRQ (frequency protein), FRH (FRQ-interacting RNA helicase), and WC1 and WC2 (white collar proteins) are major clock elements that govern the circadian rhythm in <i>Neurospora</i><i>crassa</i>. However, deletion of <i>frh</i> is lethal for the viability of <i>N. crassa</i>, making it elusive whether FRH is essential or nonessential for the circadian rhythm. This needs clarification in a fungus where <i>frh</i> deletion is not lethal. Here, the nuclear FRH ortholog proved nonessential for the circadian rhythm of <i>Metarhizium</i><i>robertsii</i>. The nucleocytoplasmic shuttling of <i>M. robertsii</i> FRQ, WC1, and WC2 orthologs was light-dependent. Yeast two-hybrid assay validated interactions of FRQ with FRH and WC1 instead of FRH with WC1 and WC2 or FRQ with WC2. The circadian rhythm welJournal of fungi (Basel, Switzerland)The Essential and the Nonessential Roles of Four Clock Elements in the Circadian Rhythm of <i>Metarhizium</i><i>robertsii</i>.PMC92246702022C0205831772218Peng HZhang YLYing SHFeng MGfalseThe Essential and the Nonessential Roles of Four Clock Elements in the Circadian Rhythm of <i>Metarhizium</i><i>robertsii</i>.FRQ (frequency protein), FRH (FRQ-interacting RNA helicase), and WC1 and WC2 (white collar proteins) are major clock elements that govern the circadian rhythm in <i>Neurospora</i><i>crassa</i>. However, deletion of <i>frh</i> is lethal for the viability of <i>N. crassa</i>, making it elusive whether FRH is essential or nonessential for the circadian rhythm. This needs clarification in a fungus where <i>frh</i> deletion is not lethal. Here, the nuclear FRH ortholog proved nonessential for the circadian rhythm of <i>Metarhizium</i><i>robertsii</i>. The nucleocytoplasmic shuttling of <i>M. robertsii</i> FRQ, WC1, and WC2 orthologs was light-dependent. Yeast two-hybrid assay validated interactions of FRQ with FRH and WC1 instead of FRH with WC1 and WC2 or FRQ with WC2. The circadian rhythm wel2022-01-01T00:00:00Z2022 May2025-08-31T03:17:25.079Z2025-02-19T02:15:37.484ZS-EPMC92246703573604110.3390/jof8060558