title: The mitotic PP2A regulator ENSA/ARPP-19 is remarkably conserved across plants and most eukaryotes.
abstract: Protein phosphatase 2A (PP2A) is a major serine/threonine phosphatase of eukaryotes. PP2A containing the B55 subunit is a key regulator of mitosis and must be inhibited by phosphorylated α-endosulfine (ENSA) or cyclic AMP-regulated 19 kDa phosphoprotein (ARPP-19) to allow passage through mitosis. Exit from mitosis then requires dephosphorylation of ENSA/ARPP-19 to relieve inhibition of PP2A/B55. ENSA/ARPP-19 has been characterized in several vertebrates and budding yeast, but little is known about its presence in plants and the majority of other eukaryotes. Here we show that three isoforms of ENSA/ARPP-19 are present in the Arabidopsis thaliana genome with distinct expression profiles across various plant tissues. The ENSA/ARPP-19 proteins, and in particular their key inhibitory sequence FDSGDY (FDSADW in plants), is remarkably conserved across plants and most eukaryotes suggesting an ancient origin and conserved function to control PP2A activity.
authors: Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada.
authors: Anne-Marie
authors: AM
authors: Labandera
authors: Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada.
authors: Ahmad R
authors: AR
authors: Vahab
authors: Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada.
authors: Sibapriya
authors: S
authors: Chaudhuri
authors: Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada.
authors: David
authors: D
authors: Kerk
authors: Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada. Electronic address: moorhead@ucalgary.ca.
authors: Greg B G
authors: GB
authors: Moorhead
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017360:Arabidopsis / Q000737:chemistry / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019295:Computational Biology; D056890:Eukaryota; D018506:Gene Expression Regulation, Plant; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D008938:Mitosis; D008969:Molecular Sequence Data; D010455:Peptides / Q000378:metabolism*; D010750:Phosphoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D054648:Protein Phosphatase 2 / Q000378:metabolism*; D016415:Sequence Alignment
chemical_list: D029681:Arabidopsis Proteins; D036341:Intercellular Signaling Peptides and Proteins; D010455:Peptides; D010750:Phosphoproteins; D020033:Protein Isoforms; C064321:cyclic AMP-regulated phosphoprotein 19; C075663:endosulfine; D054648:Protein Phosphatase 2
keywords: ARPP-19; ENSA; Greatwall; Mitosis; PP2A; α–endosulfine