Source 1primary paper2020Journal of Experimental Botany
Toolkit/PHYTOCHROME RAPIDLY REGULATED1
PHYTOCHROME RAPIDLY REGULATED1
Also known as: PAR1
Taxonomy: Mechanism Branch / Component. Workflows sit above the mechanism and technique branches rather than replacing them.
Summary
PHYTOCHROME RAPIDLY REGULATED1 (PAR1) is a non-DNA-binding atypical helix-loop-helix (HLH) inhibitor implicated in light-regulated transcriptional control in plants. In the cited study, PAR1 suppresses cell elongation by interfering with the DNA-binding activity of the bHLH transcription factor CIB1.
Usefulness & Problems
Why this is useful
PAR1 is useful as a regulatory protein domain for attenuating transcription factor output without directly binding DNA. The cited evidence supports its use for modulating light- and heat-inducible cell elongation programs through inhibition of CIB1-dependent transcription.
Problem solved
PAR1 helps solve the problem of suppressing transcriptional programs that drive cell elongation when those programs are activated by upstream light- and heat-responsive bHLH factors. Specifically, it counteracts CIB1 DNA-binding activity within a two-step HLH/bHLH regulatory system.
Taxonomy & Function
Primary hierarchy
Mechanism Branch
Component: A low-level protein part used inside a larger architecture that realizes a mechanism.
Mechanisms
DNA Bindinghlh-mediated transcriptional inhibitioninterference with dna binding activityinterference with promoter bindingTechniques
No technique tags yet.
Target processes
transcriptionInput: Light
Implementation Constraints
The evidence supports PAR1 as an atypical HLH protein domain that does not itself bind DNA, so implementation would depend on expression in a context containing its relevant transcription factor partners such as CIB1. The supplied material does not report construct architecture, cofactors, delivery methods, or heterologous expression requirements.
Evidence is limited to a single cited study and a narrow functional context centered on CIB1-regulated cell elongation. The supplied evidence does not provide quantitative performance data, domain boundaries, structural information, or validation across multiple organisms or engineering settings.
Validation
Cell-freeBacteriaMammalianMouseHumanTherapeuticIndep. Replication
Supporting Sources
Ranked Claims
CIB1 activates genes that function in cell elongation.
CIB1 activates genes that function in cell elongation
PIF4 directly regulates CIB1 expression by interacting with the CIB1 promoter.
Furthermore, PIF4 directly regulates CIB1 expression by interacting with its promoter
PIF4 directly regulates CIB1 expression by interacting with the CIB1 promoter.
Furthermore, PIF4 directly regulates CIB1 expression by interacting with its promoter
PIF4 directly regulates CIB1 expression by interacting with the CIB1 promoter.
Furthermore, PIF4 directly regulates CIB1 expression by interacting with its promoter
PIF4 directly regulates CIB1 expression by interacting with the CIB1 promoter.
Furthermore, PIF4 directly regulates CIB1 expression by interacting with its promoter
PIF4 directly regulates CIB1 expression by interacting with the CIB1 promoter.
Furthermore, PIF4 directly regulates CIB1 expression by interacting with its promoter
PIF4 directly regulates CIB1 expression by interacting with the CIB1 promoter.
Furthermore, PIF4 directly regulates CIB1 expression by interacting with its promoter
PIF4 directly regulates CIB1 expression by interacting with the CIB1 promoter.
Furthermore, PIF4 directly regulates CIB1 expression by interacting with its promoter
PAR1 interferes with the DNA binding activity of CIB1, thereby suppressing cell elongation.
PAR1 interferes with the DNA binding activity of CIB1, thus suppressing cell elongation
PAR1 interferes with the DNA binding activity of CIB1, thereby suppressing cell elongation.
PAR1 interferes with the DNA binding activity of CIB1, thus suppressing cell elongation
PAR1 interferes with the DNA binding activity of CIB1, thereby suppressing cell elongation.
PAR1 interferes with the DNA binding activity of CIB1, thus suppressing cell elongation
PAR1 interferes with the DNA binding activity of CIB1, thereby suppressing cell elongation.
PAR1 interferes with the DNA binding activity of CIB1, thus suppressing cell elongation
PAR1 interferes with the DNA binding activity of CIB1, thereby suppressing cell elongation.
PAR1 interferes with the DNA binding activity of CIB1, thus suppressing cell elongation
PAR1 interferes with the DNA binding activity of CIB1, thereby suppressing cell elongation.
PAR1 interferes with the DNA binding activity of CIB1, thus suppressing cell elongation
PAR1 interferes with the DNA binding activity of CIB1, thereby suppressing cell elongation.
PAR1 interferes with the DNA binding activity of CIB1, thus suppressing cell elongation
PAR1 and HFR1 interfere with PIF4 binding to the CIB1 promoter.
PAR1 and HFR1 interfere with PIF4 binding to the CIB1 promoter
PAR1 and HFR1 interfere with PIF4 binding to the CIB1 promoter.
PAR1 and HFR1 interfere with PIF4 binding to the CIB1 promoter
PAR1 and HFR1 interfere with PIF4 binding to the CIB1 promoter.
PAR1 and HFR1 interfere with PIF4 binding to the CIB1 promoter
PAR1 and HFR1 interfere with PIF4 binding to the CIB1 promoter.
PAR1 and HFR1 interfere with PIF4 binding to the CIB1 promoter
PAR1 and HFR1 interfere with PIF4 binding to the CIB1 promoter.
PAR1 and HFR1 interfere with PIF4 binding to the CIB1 promoter
PAR1 and HFR1 interfere with PIF4 binding to the CIB1 promoter.
PAR1 and HFR1 interfere with PIF4 binding to the CIB1 promoter
PAR1 and HFR1 interfere with PIF4 binding to the CIB1 promoter.
PAR1 and HFR1 interfere with PIF4 binding to the CIB1 promoter
CIB1 positively regulates cell elongation in Arabidopsis thaliana under the control of PIF4, PAR1, and HFR1.
Here, we show that in Arabidopsis thaliana, the bHLH transcription factor CRYPTOCHROME-INTERACTING BASIC HELIX-LOOP-HELIX 1 (CIB1) positively regulates cell elongation under the control of PIF4, PAR1, and HFR1.
CIB1 positively regulates cell elongation in Arabidopsis thaliana under the control of PIF4, PAR1, and HFR1.
Here, we show that in Arabidopsis thaliana, the bHLH transcription factor CRYPTOCHROME-INTERACTING BASIC HELIX-LOOP-HELIX 1 (CIB1) positively regulates cell elongation under the control of PIF4, PAR1, and HFR1.
CIB1 positively regulates cell elongation in Arabidopsis thaliana under the control of PIF4, PAR1, and HFR1.
Here, we show that in Arabidopsis thaliana, the bHLH transcription factor CRYPTOCHROME-INTERACTING BASIC HELIX-LOOP-HELIX 1 (CIB1) positively regulates cell elongation under the control of PIF4, PAR1, and HFR1.
CIB1 positively regulates cell elongation in Arabidopsis thaliana under the control of PIF4, PAR1, and HFR1.
Here, we show that in Arabidopsis thaliana, the bHLH transcription factor CRYPTOCHROME-INTERACTING BASIC HELIX-LOOP-HELIX 1 (CIB1) positively regulates cell elongation under the control of PIF4, PAR1, and HFR1.
CIB1 positively regulates cell elongation in Arabidopsis thaliana under the control of PIF4, PAR1, and HFR1.
Here, we show that in Arabidopsis thaliana, the bHLH transcription factor CRYPTOCHROME-INTERACTING BASIC HELIX-LOOP-HELIX 1 (CIB1) positively regulates cell elongation under the control of PIF4, PAR1, and HFR1.
CIB1 positively regulates cell elongation in Arabidopsis thaliana under the control of PIF4, PAR1, and HFR1.
Here, we show that in Arabidopsis thaliana, the bHLH transcription factor CRYPTOCHROME-INTERACTING BASIC HELIX-LOOP-HELIX 1 (CIB1) positively regulates cell elongation under the control of PIF4, PAR1, and HFR1.
CIB1 positively regulates cell elongation in Arabidopsis thaliana under the control of PIF4, PAR1, and HFR1.
Here, we show that in Arabidopsis thaliana, the bHLH transcription factor CRYPTOCHROME-INTERACTING BASIC HELIX-LOOP-HELIX 1 (CIB1) positively regulates cell elongation under the control of PIF4, PAR1, and HFR1.
Two antagonistic HLH/bHLH systems, PIF4-PAR1/HFR1 and CIB1-PAR1, regulate cell elongation in response to light and high temperature.
Hence, two antagonistic HLH/bHLH systems, the PIF4-PAR1/HFR1 and CIB1-PAR1 systems, regulate cell elongation in response to light and high temperature.
Two antagonistic HLH/bHLH systems, PIF4-PAR1/HFR1 and CIB1-PAR1, regulate cell elongation in response to light and high temperature.
Hence, two antagonistic HLH/bHLH systems, the PIF4-PAR1/HFR1 and CIB1-PAR1 systems, regulate cell elongation in response to light and high temperature.
Two antagonistic HLH/bHLH systems, PIF4-PAR1/HFR1 and CIB1-PAR1, regulate cell elongation in response to light and high temperature.
Hence, two antagonistic HLH/bHLH systems, the PIF4-PAR1/HFR1 and CIB1-PAR1 systems, regulate cell elongation in response to light and high temperature.
Two antagonistic HLH/bHLH systems, PIF4-PAR1/HFR1 and CIB1-PAR1, regulate cell elongation in response to light and high temperature.
Hence, two antagonistic HLH/bHLH systems, the PIF4-PAR1/HFR1 and CIB1-PAR1 systems, regulate cell elongation in response to light and high temperature.
Two antagonistic HLH/bHLH systems, PIF4-PAR1/HFR1 and CIB1-PAR1, regulate cell elongation in response to light and high temperature.
Hence, two antagonistic HLH/bHLH systems, the PIF4-PAR1/HFR1 and CIB1-PAR1 systems, regulate cell elongation in response to light and high temperature.
Two antagonistic HLH/bHLH systems, PIF4-PAR1/HFR1 and CIB1-PAR1, regulate cell elongation in response to light and high temperature.
Hence, two antagonistic HLH/bHLH systems, the PIF4-PAR1/HFR1 and CIB1-PAR1 systems, regulate cell elongation in response to light and high temperature.
Two antagonistic HLH/bHLH systems, PIF4-PAR1/HFR1 and CIB1-PAR1, regulate cell elongation in response to light and high temperature.
Hence, two antagonistic HLH/bHLH systems, the PIF4-PAR1/HFR1 and CIB1-PAR1 systems, regulate cell elongation in response to light and high temperature.
Approval Evidence
1 source4 linked approval claimsfirst-pass slug phytochrome-rapidly-regulated1
the non-DNA binding atypical HLH inhibitors PHYTOCHROME RAPIDLY REGULATED1 (PAR1)
Source:
interferes with dna binding activitysupports
PAR1 interferes with the DNA binding activity of CIB1, thereby suppressing cell elongation.
PAR1 interferes with the DNA binding activity of CIB1, thus suppressing cell elongation
Source:
interferes with promoter bindingsupports
PAR1 and HFR1 interfere with PIF4 binding to the CIB1 promoter.
PAR1 and HFR1 interfere with PIF4 binding to the CIB1 promoter
Source:
regulates biological processsupports
CIB1 positively regulates cell elongation in Arabidopsis thaliana under the control of PIF4, PAR1, and HFR1.
Here, we show that in Arabidopsis thaliana, the bHLH transcription factor CRYPTOCHROME-INTERACTING BASIC HELIX-LOOP-HELIX 1 (CIB1) positively regulates cell elongation under the control of PIF4, PAR1, and HFR1.
Source:
regulatory system modelsupports
Two antagonistic HLH/bHLH systems, PIF4-PAR1/HFR1 and CIB1-PAR1, regulate cell elongation in response to light and high temperature.
Hence, two antagonistic HLH/bHLH systems, the PIF4-PAR1/HFR1 and CIB1-PAR1 systems, regulate cell elongation in response to light and high temperature.
Source:
Comparisons
Source-backed strengths
The available evidence identifies a specific inhibitory function: PAR1 interferes with CIB1 DNA binding and thereby suppresses cell elongation. Its classification as a non-DNA-binding atypical HLH inhibitor is consistent with a transcriptional repression role mediated through protein-level interference rather than direct promoter recognition.
Ranked Citations
- 1.