WC-1 and the Proximal GATA Sequence Mediate a Cis-/Trans-Acting Repressive Regulation of Light-Dependent Gene Transcription in the Dark

Abstract

Light influences a wide range of physiological processes from prokaryotes to mammals. Neurospora crassa represents an important model system used for studying this signal pathway. At molecular levels, the WHITE COLLAR Complex (WCC), a heterodimer formed by WC-1 (the blue light photo-sensor) and WC-2 (the transcriptional activator), is the critical positive regulator of light-dependent gene expression. GATN (N indicates any other nucleotide) repeats are consensus sequences within the promoters of light-dependent genes recognized by the WCC. The distal GATN is also known as C-box since it is involved in the circadian clock. However, we know very little about the role of the proximal GATN, and the molecular mechanism that controls the transcription of light-induced genes during the dark/light transition it is still unclear. Here we showed a first indication that mutagenesis of the proximal GATA sequence within the target promoter of the albino-3 gene or deletion of the WC-1 zinc finger domain led to a rise in expression of light-dependent genes already in the dark, effectively decoupling light stimuli and transcriptional activation. This is the first observation of cis-/trans-acting repressive machinery, which is not consistent with the light-dependent regulatory mechanism observed in the eukaryotic world so far.

Genome-Wide Investigation and Expression Profiling Under Abiotic Stresses of a Soybean Unknown Function (DUF21) and Cystathionine-β-Synthase (CBS) Domain-Containing Protein Family

“…The table describes information pertaining to functions, such as elements in response to hormones, including abscisic acid (ABRE, CE1, and MRE) (Narusaka et al 2003 ), salicylic acid (TCA element) (Liu et al 2020 ), ethylene (ERE) (Song et al 2019 ), gibberellin acid (GARE-motif, P-box and TATC-box) (Zhang et al 2017 ), auxin (TGA-element) (Xin et al 2016 ), MeJA (CGTCA-motif and TGACG-motif) (Yu et al 2018 ), temperature-responsive elements (HSE and LTR) (Wu et al . 2019 ), drought-inducible elements (MBS) (Xu et al 2019 ), wound-responsive element (WUN-motif), defense and stress element (TC-rich repeats) (Li et al 2019 ), salt-inducible element (GT1-motif), anaerobic induction element (ARE), and light- and nitrogen-inducible element (GATA-motif) (Brenna and Talora 2019 ). As shown in Table 2 , ABRE, MBS, TCA element, GARE-motif, and HSE were all present in the promoters of most of the GmCBSDUF genes, while the WUN-motif was found only in GmCBSDUF2; P-box in GmCBSDUF10; CE1 in GmCBSDUF16; TATC-box in GmCBSDUF4/6; LTR in GmCBSDUF9/13/18; and GATA-motif in GmCBSDUF5/6/10/13/15/17.…”

Impact of the White Collar Photoreceptor WcoA on the Fusarium fujikuroi Transcriptome

“…Similarly, early responsive genes were only found among the light-induced ones in F. fujikuroi . WC-1 can also act a as a repressor protein, as recently demonstrated using the photoinducible al-3 gene as a model, in which a light responsive GATA element was found to be involved in the binding of WC-1 to form a repressing complex in the dark ( Brenna and Talora, 2019 ). However, lack of early gene repression by light in N. crassa may be also explained by the action of other negative regulators, which would be activated earlier by WC-1.…”

GATA transcription factor WC2 regulates the biosynthesis of astaxanthin in yeast Xanthophyllomyces dendrorhous

“…CDZ96450.1) in X. dendrorhous in this study. Structure analysis showed that XdWC1 had no DNA‐binding domain, indicating that it was not a transcriptional repressor, unlike the WC1 in N. crassa (Ballario et al, 1996 ; Brenna & Talora, 2019 ) (Figure 7A ). The expression of XdWC1 did not change significantly in the transcriptomic analysis.…”

“…In contrast to the WCC in X. dendrorhous , the WCC in N. crassa needs white light to activate to regulate gene transcription (Linden & Macino, 1997 ; Schmidhauser et al, 1994 ). The WC1 of N. crassa represses gene expression in darkness through a GATA zinc‐finger domain combining with promoters (Brenna & Talora, 2019 ), while the WC1 of X. dendrorhous has no GATA zinc‐finger domains. These data showed the unique aspect of the metabolic regulation of astaxanthin synthesis in X. dendrorhous .…”