Zc3h10 Acts as a Transcription Factor and Is Phosphorylated to Activate the Thermogenic Program

Abstract

SUMMARY Brown adipose tissue harbors UCP1 to dissipate chemical energy as heat. However, the transcriptional network that governs the thermogenic gene program is incompletely understood. Zc3h10, a CCCH-type zinc finger protein, has recently been reported to bind RNA. However, we report here that Zc3h10 functions as a transcription factor to activate UCP1 not through the enhancer region, but by binding to a far upstream region of the UCP1 promoter. Upon sympathetic stimulation, Zc3h10 is phosphorylated at S126 by p38 mitogen-activated protein kinase (MAPK) to increase binding to the distal region of the UCP1 promoter. Zc3h10, as well as mutant Zc3h10, which cannot bind RNA, enhances thermogenic capacity and energy expenditure, protecting mice from diet-induced obesity. Conversely, Zc3h10 ablation in UCP1+ cells in mice impairs thermogenic capacity and lowers oxygen consumption, leading to weight gain. Hence, Zc3h10 plays a critical role in the thermogenic gene program and may present future targets for obesity therapeutics.

Dot1L interacts with Zc3h10 to activate UCP1 and other thermogenic genes

“…As expected, Dot1L-BKO mice showed a 60% reduction in Dot1L mRNA levels in BAT ( Figure 4H). As we previously have reported that overexpression Zc3h10 in adipose tissue enhances thermogenic gene expression (Yi et al, 2019), Zc3h10 overexpressing mice by injection had increased expression of BAT-enriched genes, such as UCP1, Cox8b, and CideA, compared to the control mice. More importantly, expression BATenriched genes remained significantly reduced in Dot1L-BKO even upon Zc3h10 overexpression, while adipogenic markers, such as PPARg, remained unchanged ( Figure 4H).…”

“…We performed chromatin immunoprecipitation (ChIP) using BAT cells transduced with adenovirus containing Flag-tagged Zc3h10 and HA-tagged Dot1L. By using Flag (for Zc3h10) and HA (for Dot1L) antibodies, we detected strong enrichment of both Zc3h10 and Dot1L at the -4.6 kb region of the UCP1 promoter, a region corresponding to the Zc3h10 binding site (Yi et al, 2019) (Figure 1G, right). This illustrates co-occupancy of Dot1L and Zc3h10 at the same region of the UCP1 promoter.…”

“…A multitude of transcriptional regulators have been implicated in the transcription of UCP1, including transcription factors, Zfp516, IRF4 and EBF2, and transcriptional coregulators, PRDM16, PGC1a and LSD1 (Seale et al, 2008, Rajakumari et al, 2013, Dempersmier et al, 2015, Puigserver et al, 1998, Sambeat et al, 2016, Kong et al, 2014. Recently, we identified a BAT-enriched and cold-induced transcription factor, Zc3h10 that activates the UCP1 and other target genes, such as Tfam and Nrf1 for mitochondrial biogenesis (Yi et al, 2019). Zc3h10 activates the UCP1 promoter by directly binding to the -4.6 kb region.…”

β-adrenergic receptor signaling evokes the PKA-ASK axis in mature brown adipocytes

“…Conversely, p38 is activated in both immature and mature brown adipocytes (Fig 1) [9]. Some pioneering works mainly executed by Dr. Collins laboratory have shown that βAR agonists evoke p38 activation in multiple adipocyte cell lines, differentiated brown adipocytes, and in vivo [16–19]. MKK3 may function as a MAP2K, connecting ASK1 and p38 [18].…”

“…Clinically, constructing selective methods for activating β 3 AR on brown and/or beige adipocytes is crucial, but it is of critical importance to understand the signaling mechanisms induced by β 3 AR agonists in mature brown adipocytes to fully understand the potential side effects of β 3 AR agonism. However, a limited number of studies have uncovered the involvement of several kinases in β 3 AR signaling [16–19]; specifically, the downstream targets of PKA are not fully known.…”