RETRACTED ARTICLE: PPP1, a plant-specific regulator of transcription controls Arabidopsis development and PIN expression

Abstract

Directional transport of auxin is essential for plant development, with PIN auxin transport proteins representing an integral part of the machinery that controls hormone distribution. However, unlike the rapidly emerging framework of molecular determinants regulating PIN protein abundance and subcellular localization, insights into mechanisms controlling PIN transcription are still limited. Here we describe PIN2 PROMOTER BINDING PROTEIN 1 (PPP1), an evolutionary conserved plant-specific DNA binding protein that acts on transcription of PIN genes. Consistent with PPP1 DNA-binding activity, PPP1 reporter proteins are nuclear localized and analysis of PPP1 null alleles and knockdown lines indicated a function as a positive regulator of PIN expression. Furthermore, we show that ppp1 pleiotropic mutant phenotypes are partially reverted by PIN overexpression, and results are presented that underline a role of PPP1-PIN promoter interaction in PIN expression control. Collectively, our findings identify an elementary, thus far unknown, plant-specific DNA-binding protein required for post-embryonic plant development, in general, and correct expression of PIN genes, in particular.

Rocks in the auxin stream: Wound-induced auxin accumulation and ERF115 expression synergistically drive stem cell regeneration

“…Although the bulk transport of auxin to distant tissues occurs passively through vascular tissues, fine-tuning and patterning are achieved by active transport. Such directional transport of auxin is largely mediated by efflux carrier proteins known as PINs that are polarly localized on the cell membranes (18,28,29). Consequently, auxin flows in a "reverse-fountain" pattern that is sustained by coordinated PIN activity and local auxin biosynthesis.…”

“…To understand how ERF115 might regulate the response to auxin accumulation caused by DNA damage-induced cell death, we looked at the components of auxin signaling differentially regulated in our BLM transcriptome dataset. Among these were several members of the AUX/IAA (IAA1, 5,13,19,20,29,33) and AUXIN RESPONSE FACTOR (ARF3, 5, 8) gene families that regulate TIR1/AFB receptor-mediated auxin signaling (Fig. 6 A and B) (11).…”

The PIN-FORMED Auxin Efflux Carriers in Plants

“…A plant-specific DNA binding protein with an unknown function, PIN2 PROMOTER BINDING PROTEIN 1 (PPP1), was identified as a PIN2 regulator by the yeast one-hybrid methodology. In silico analysis revealed that parts of PPP1 DNA-binding sites commonly exist in the promoter regions of most PIN genes [ 96 ]. Recently, an Apetala2 (AP2) transcription factor, WRINKLED1 (WRI1), which is involved in fatty acid biosynthesis, has been show to directly target the promoters of PIN4 and PIN5 and cause reduced expression levels of some PIN genes (e.g., PIN1 , PIN3 and PIN5 - 6 ) in the wri1-1 mutant background compared to wildtype specimens [ 97 ].…”

Functional Coordination of the Chromatin-Remodeling Factor AtINO80 and the Histone Chaperones NRP1/2 in Inflorescence Meristem and Root Apical Meristem

“…Similar feedback mechanism is also used in RAM by PLT transcription factors (Blilou et al, 2005; Xu et al, 2006). In addition, more recent studies have revealed additional sequence-specific transcription factors targeting the PIN1 gene, including MADS-domain transcription factor AGAMOUS-like 14 (AGL14) (Garay-Arroyo et al, 2013) and PIN2 PROMOTER BINDING PROTEIN 1 (PPP1), an evolutionary conserved plant-specific DNA binding protein (Benjamins et al, 2016). Currently, there is no evidence to support that AtINO80 and NRP1/2 possess any sequence-specific DNA-binding ability.…”