NCBI Accession #
NP_001078102.1
NCBI GenBank Nucleotide #
NM_001084633.1
NCBI Official Full Name
response regulator 22
NCBI Official Symbol
RR22
NCBI Official Synonym Symbols
ARR22; response regulator 22; T6K12.10; T6K12_10
NCBI Protein Information
response regulator 22
NCBI Summary
Encodes an atypical subtype of the ARR (Arabidopsis response regulator) protein family. ARR22 is more similar to the receiver domains of hybrid kinases than other response regulators. It acts as a phosphohistidine phosphatase when tested with phospho-AHP5 in vitro suggesting that it might be involved in a two-component phosphorelay. Expression of ARR22 transcripts appears to be localized to the chalaza and to be induced by wounding. Ectopic expression of ARR in other parts of the plant leads to reduced cytokinin-related responses and impaired root, shoot, and flower development. Overexpression of wild-type ARR22 in an arr22 mutant background causes variable defects in plant growth and fertility. But, in the same ar22 background, over-expression of versions of ARR22 that should act as dominant-negative or constitutively active proteins, based on mutations to the conserved Asp residue, do not show any phenotypic abnormalities, raising the possibility that these may not act as canonical response regulators.
UniProt Protein Name
Two-component response regulator ARR22
UniProt Primary Accession #
Q9M8Y4
UniProt Related Accession #
Q9M8Y4
UniProt Comments
Functions as response regulator involved in His-to-Asp phosphorelay signal transduction system. Phosphorylation of the Asp residue in the receiver domain activates the ability of the protein to promote the transcription of target genes. Type-A response regulators seem to act as negative regulators of the cytokinin signaling .