RRC ID 12327
Author Templeton GW, Nimick M, Morrice N, Campbell D, Goudreault M, Gingras AC, Takemiya A, Shimazaki K, Moorhead GB.
Title Identification and characterization of AtI-2, an Arabidopsis homologue of an ancient protein phosphatase 1 (PP1) regulatory subunit.
Journal Biochem. J.
Abstract PP1 (protein phosphatase 1) is among the most conserved enzymes known, with one or more isoforms present in all sequenced eukaryotic genomes. PP1 dephosphorylates specific serine/threonine phosphoproteins as defined by associated regulatory or targeting subunits. In the present study we performed a PP1-binding screen to find putative PP1 interactors in Arabidopsis thaliana and uncovered a homologue of the ancient PP1 interactor, I-2 (inhibitor-2). Bioinformatic analysis revealed remarkable conservation of three regions of plant I-2 that play key roles in binding to PP1 and regulating its function. The sequence-related properties of plant I-2 were compared across eukaryotes, indicating a lack of I-2 in some species and the emergence points from key motifs during the evolution of this ancient regulator. Biochemical characterization of AtI-2 (Arabidopsis I-2) revealed its ability to inhibit all plant PP1 isoforms and inhibitory dependence requiring the primary interaction motif known as RVXF. Arabidopsis I-2 was shown to be a phosphoprotein in vivo that was enriched in the nucleus. TAP (tandem affinity purification)-tag experiments with plant I-2 showed in vivo association with several Arabidopsis PP1 isoforms and identified other potential I-2 binding proteins.
Volume 435(1)
Pages 73-83
Published 2011-4-1
DOI 10.1042/BJ20101035
PII BJ20101035
PMID 21222654
MeSH Amino Acid Sequence Arabidopsis / genetics Arabidopsis / metabolism* Arabidopsis Proteins / chemistry* Arabidopsis Proteins / genetics Arabidopsis Proteins / isolation & purification Arabidopsis Proteins / metabolism Cell Line Cell Nucleus / metabolism Computational Biology / methods Databases, Protein Molecular Sequence Data Phosphoproteins / chemistry Phosphoproteins / genetics Phosphoproteins / isolation & purification Phosphoproteins / metabolism Phylogeny Plant Epidermis / cytology Plant Epidermis / metabolism Plant Leaves / cytology Plant Leaves / metabolism Plant Structures / metabolism Protein Isoforms / genetics Protein Isoforms / isolation & purification Protein Isoforms / metabolism Protein Phosphatase 1 / chemistry* Protein Phosphatase 1 / genetics Protein Phosphatase 1 / isolation & purification Protein Phosphatase 1 / metabolism Protein Subunits / chemistry Protein Subunits / genetics Protein Subunits / isolation & purification Protein Subunits / metabolism Protein Transport Recombinant Fusion Proteins / metabolism Sequence Alignment Sequence Homology, Amino Acid
IF 4.331
Times Cited 22
Arabidopsis / Cultured plant cells, genes pda02740