PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 11788306

Environmental cues affecting development.

Jorge J Casal
View original source ↗Export metadata ↓

Abstract

Multiple receptors connect environmental cues to developmental genes via shortcuts and more tortuous pathways, creating a network of interactive signals in which negative regulators play a key role. The elements of the circuitry, their connections, and their functional significance are being uncovered thanks to the analysis of genetic interactions, protein-protein interactions, sub-cellular localisation and transcriptome patterns.

Explore related subjects

Arabidopsis ProteinsCarrier ProteinsCell NucleusCytoplasmEnvironmentGene Expression Regulation, DevelopmentalGene Expression Regulation, PlantPlant DevelopmentPlant ProteinsPlantsReceptor Cross-TalkReceptors, Cell SurfaceRepressor ProteinsSignal TransductionTranscription, GeneticUbiquitin-Protein LigasesJournal ArticleResearch Support, Non-U.S. Gov'tReview

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Jorge J Casal. 2002. Environmental cues affecting development.. https://doi.org/10.1016/s1369-5266(01)00218-7

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2025

Bimodal retrograde signaling disrupts a suppressor network and activates a key transcriptional activator to direct stress responses.

Plastid-to-nucleus communication, crucial for regulating stress-responsive gene expression, has long intrigued researchers. This study reveals how the plastidial metabolite 2-C-methyl-D-erythritol-2,4-cyclopyrophosphate (MEcPP) orchestrates transcriptional reprogramming by modulating the rapid stress response element (RSRE), a conserved regulatory hub in the plant general stress response network. Yeast one-hybrid assays identified HAT1, a class II HD-Zip protein, as a negative regulator of RSRE. Genetic analyses, including HAT1 overexpression and knockdowns, confirmed its role in suppressing RSRE activity. Interaction assays uncovered a suppression network involving HAT1, the co-repressor TOPLESS (TPL), and the nuclear importin IMPα-9. Furthermore, HAT1 interacts with calmodulin-binding transcription activator 3 (CAMTA3), a calcium/calmodulin-binding transcription factor known to activate RSRE. AlphaFold modeling provided insights into the architecture of the HAT1-RSRE complex and HAT-CAMTA3 interaction, supported by conserved domains across plant species. Under stress condition, MEcPP accumulation promotes the 26S proteasomal degradation of TPL and IMPα-9 while reduces auxin-dependent HAT1 expression. Additionally, MEcPP enhances Ca2+ influx, activating CAMTA3 and enabling it to bind RSRE, thereby initiating the transcription of stress response genes. This dual mechanism-dismantling suppressors (HAT1, TPL, and IMPα-9) and activating CAMTA3-underscores MEcPP's central role in plastid-to-nucleus signaling. These findings emphasize MEcPP's pivotal function in dynamically regulating gene expression to maintain cellular homeostasis under environmental stress.

Arabidopsis Proteins↗
PubMed2003

Differential substrate-induced signaling through the TonB-dependent transporter BtuB.

The BtuB transporter mediates high-affinity binding and TonB-dependent active transport of vitamin B12 [cyanocobalamin (CNCbl)] across the outer membrane of Escherichia coli. A characteristic feature of TonB-dependent transporters is the Ton box, a conserved sequence near the N terminus and exposed to the periplasm. Crosslinking to TonB and site-directed spin labeling indicated that the Ton box of BtuB undergoes a substantial conformational transition in response to CNCbl binding, but only slight movement was seen in crystal structures. An in vivo method of detecting substrate-induced changes in the Ton box environment measured reaction of a biotin maleimide derivative with cysteine substitutions through the N-terminal region of BtuB between positions 1 and 31. The degree of maleimide labeling of different residues correlated with their accessibility in the crystal structure. Labeling of many positions was increased strongly when CNCbl was present, consistent with the undocking of this region proposed from spin-labeling analyses. The receptor-binding domain of colicin E3, which binds to BtuB competitively with CNCbl, resulted in decreased labeling. Both substrate-induced transitions occur in and beyond the Ton box and were affected by transport-uncoupling substitutions. Thus, two transport substrates that bind competitively to the extracellular face of BtuB stabilize opposite transitions of the Ton box.

Arabidopsis Proteins↗
PubMed2003

The Arabidopsis 14-3-3 protein, GF14omega, binds to the Schizosaccharomyces pombe Cdc25 phosphatase and rescues checkpoint defects in the rad24- mutant.

The fission yeast (S. pombe) mitotic inducer gene, Spcdc25, interacts with the plant cell cycle to establish a small cell size phenotype compared with wild-type cells. We have investigated the nature of this interaction by yeast two-hybrid screening using Spcdc25 as bait in a cDNA library prepared from root tips of Arabidopsis thaliana (L.) Heynh. Three 14-3-3 proteins were detected: G-box Factor-like (GF)14kappa, lambda and omega; binding with Spcdc25 was confirmed by an independent immunoprecipitation assay. To test for cell cycle checkpoint function, GF14kappa, lambda and omega were transformed independently, using the strong nmt1+ promoter, into rad24-, a fission yeast mutant deficient in a 14-3-3 checkpoint protein. When exposed to UV irradiation or in the presence of 10 mM hydroxyurea, only cells transformed with GF14omega could fully rescue the defects in the DNA-damage and DNA-replication checkpoints of this mutant. Supporting evidence for a GF14omega cell cycle function was provided by semi-quantitative reverse transcription-polymerase chain reaction indicating that expression of this gene was elevated in regions of the plant that comprise dividing cells whereas GF14kappa and lambda expression was more evenly detected in all tissues examined. The data are consistent with the hypothesis that interaction between Spcdc25 and the plant cell cycle occurs at the level of a 14-3-3 protein with distinct checkpoint properties.

Arabidopsis Proteins↗