USP2 Regulates the Intracellular Localization of PER1 and Circadian Gene Expression

Abstract

Endogenous 24-h rhythms in physiology are driven by a network of circadian clocks located in most tissues. The molecular clock mechanism is based on feedback loops involving clock genes and their protein products. Posttranslational modifications, including ubiquitination, are important for regulating the clock feedback mechanism. Recently, we showed that the deubiquitinating enzyme ubiquitin-specific peptidase 2 (USP2) associates with clock proteins and deubiquitinates PERIOD1 (PER1) but does not affect its overall stability. Mice devoid of USP2 display defects in clock function. Here, we show that USP2 regulates nucleocytoplasmic shuttling and nuclear retention of PER1 and its repressive role on the clock transcription factors CLOCK and BMAL1. The rhythm of nuclear entry of PER1 in Usp2 knockout mouse embryonic fibroblasts (MEFs) was advanced but with reduced nuclear accumulation of PER1. Although Per1 mRNA expression rhythm remained intact in the Usp2 KO MEFs, the expression profiles of other core clock genes were altered. This was also true for the expression of clock-controlled genes (e.g., Dbp, Tef, Hlf, E4bp4). A similar phase advance of PER1 nuclear localization rhythm and alteration of clock gene expression profiles were also observed in livers of Usp2 KO mice. Taken together, our results demonstrate a novel function of USP2 in the molecular clock in which it regulates PER1 function by gating its nuclear entry and accumulation.

Deubiquitinase USP2a Sustains Interferons Antiviral Activity by Restricting Ubiquitination of Activated STAT1 in the Nucleus

“…We further found that USP2a ( S1 Table ), but neither USP30 nor USP52, bound to pY701-STAT1 ( S4A Fig ). The USP2 family includes two major isoforms, USP2a (69 KDa) and USP2b (45 KDa) [ 27 , 28 , 29 ]. To further investigate the role of USP2, we turned to a USP2 specific antibody, which can recognize human but not mouse USP2a and USP2b.…”

Antigen exposure in the late light period induces severe symptoms of food allergy in an OVA-allergic mouse model

“…A 50 ng aliquot of total RNA was reverse-transcribed and amplified with a One-Step SYBR reverse transcription PCR (RT-PCR) kit (TaKaRa Bio Inc, Shiga, Japan) in the PikoReal Real-Time PCR System (Thermo Fisher Scientific, Inc., Kanagawa, Japan). The specific primer pairs were designed based on published data for 18S ribosomal RNA (rRNA) , Ocln , Cldn3 , and E4bp4 genes 40 41 42 . The primer sequences are described in Supplementary Table.…”

The pineal gland: A model for adrenergic modulation of ubiquitin ligases

“…Among the proteins that USP2 (ubiquitin specific protease 2) deubiquitinates is the circadian clock protein PER1. In doing so it regulates the entry of PER1 into the nucleus [ 88 ]. Since Usp2 expression was up-regulated at night in the Hartley dataset, based on the findings of Yang et al [ 88 ] we would expect an increased nuclear accumulation of Usp2 at night in the rat pineal gland.…”

“…In doing so it regulates the entry of PER1 into the nucleus [ 88 ]. Since Usp2 expression was up-regulated at night in the Hartley dataset, based on the findings of Yang et al [ 88 ] we would expect an increased nuclear accumulation of Usp2 at night in the rat pineal gland. A role for Usp2 in regulation of circadian rhythms and Per1 was previously reported by this group based on observations on tissues of Usp2 knockout mice [ 89 ].…”