LNK1 and LNK2 recruitment to the evening element require morning expressed circadian related MYB-like transcription factors

Abstract

Transcriptional feedback loops in Arabidopsis circadian clock is composed of more repressive components, while the knowledge of activation mechanism remains limited. We recently reported 2 members from a family of NIGHT LIGHT-INDUCIBLE AND CLOCK-REGULATED genes, LNK1 and LNK2, dynamically interact with morning-phased transcriptional factors, like CIRCADIAN CLOCK ASSOCIATED1 (CCA1), LATE ELONGATED HYPOCOTYL (LHY), REVEILLE8 (RVE8) and RVE4, and function as coactivators for the expression of TIMING OF CAB EXPRESSION1 (TOC1) and PSEUDO-RESPONSE REGULATOR5 (PRR5) via transcriptional factors RVE8 and RVE4. Here we provide evidence that both LNK1 and LNK2 play critical role in the transcriptional activation of PRR5, LNK1 may contribute more than LNK2 did under experimental conditions. We also identified that both LNK1 and LNK2 recruitment to the evening element of PRR5 promoter via LNK1-RVE8 or LNK2-RVE8 proteins complex through electrophoretic mobility shift assay. Therefore LNK1 and LNK2 function as coactivator of dawn-phased MYB-like transcription factors, such as RVE8 in morning complex to regulate the target genes expression.

To Be a Flower or Fruiting Branch: Insights Revealed by mRNA and Small RNA Transcriptomes from Different Cotton Developmental Stages

“…In Arabidopsis , PRR5 can bind to LHY promoters and recruit transcriptional corepressors of the Groucho/tup1 corepressor family to repress LHY transcription in circadian clocks 50 51 . EPR1 is regulated by both phytochrome A and phytochrome B and is a component of a slave circadian oscillator in Arabidopsis 52 .…”

REVEILLE Transcription Factors Contribute to the Nighttime Accumulation of Anthocyanins in ‘Red Zaosu’ (Pyrus Bretschneideri Rehd.) Pear Fruit Skin

“…We speculated that PbRVE1a and PbRVE1b do not directly affect the PbUFGT promoter in pear. In N. benthamiana leaves, RVE1a and RVE1b may interact with other factors to active the UFGT promoter [33][34][35]. Thus, PbRVE1a, 1b and 7 increase anthocyanin accumulation by directly binding and activating PbDFR and PbANS in pear fruit.…”

“…The experiment was conducted on 12-14 June 2018. Additionally, the fruit of 'Red Zaosu' were harvested at 0, 3,6,9,12,24,27,30,33,36,48, 50, 54, 57 and 60 hours after sunrise of day 1 (HAS). The faded 'Palacer' fruitlets were used for the PbRVE virus-induced gene silencing (VIGS) assay.…”

Targeted Recruitment of the Basal Transcriptional Machinery by LNK Clock Components Controls the Circadian Rhythms of Nascent RNAs in Arabidopsis

“…Furthermore, the activation of the dusk-expressed gene TOC1/PRR1 (TIMING OF CAB EXPRESSION1/PSEUDO-RESPONSE REGULATOR1) by RVE8 is antagonized by CCA1 and involves changes in the pattern of Histone 3 acetylation at the TOC1 promoter (Farinas and Mas, 2011). Activation of TOC1 and PRR5 (another member of the TOC1/PRR1 family) occurs through direct binding of RVE8 to their promoters and requires interaction with two members of the NIGHT LIGHT-INDUCIBLE AND CLOCK-REGULATED (LNK) protein family, which together with RVEs form a transcriptional coactivator complex (Xie et al, 2014;Xing et al, 2015). In addition to altered gene expression, plants misexpressing RVE8 and/ or LNKs show a variety of phenotypes affecting anthocyanin accumulation, plant growth, and photoperiodic regulation of flowering time (Farinas and Mas, 2011;Rawat et al, 2011;Pérez-García et al, 2015;Gray et al, 2017).…”