title: Plant UBX domain-containing protein 1, PUX1, regulates the oligomeric structure and activity of arabidopsis CDC48.
abstract: p97/CDC48 is a highly abundant hexameric AAA-ATPase that functions as a molecular chaperone in numerous diverse cellular activities. We have identified an Arabidopsis UBX domain-containing protein, PUX1, which functions to regulate the oligomeric structure of the Arabidopsis homolog of p97/CDC48, AtCDC48, as well as mammalian p97. PUX1 is a soluble protein that co-fractionates with non-hexameric AtCDC48 and physically interacts with AtCDC48 in vivo. Binding of PUX1 to AtCDC48 is mediated through the UBX-containing C-terminal domain. However, disassembly of the chaperone is dependent upon the N-terminal domain of PUX1. These findings provide evidence that the assembly and disassembly of the hexameric p97/CDC48 complex is a dynamic process. This new unexpected level of regulation for p97/CDC48 was demonstrated to be critical in vivo as pux1 loss-of-function mutants display accelerated growth relative to wild-type plants. These results suggest a role for AtCDC48 and PUX1 in regulating plant growth.
authors.affiliation: Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Rancour
authors.forename: Sookhee
authors.initials: S
authors.lastname: Park
authors.forename: Seth D
authors.initials: SD
authors.lastname: Knight
authors.forename: Sebastian Y
authors.initials: SY
authors.lastname: Bednarek
mesh_terms: D000251:Adenosine Triphosphatases; D000595:Amino Acid Sequence; D000818:Animals; D017360:Arabidopsis / Q000737:chemistry / Q000196:embryology / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D018797:Cell Cycle Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002846:Chromatography, Affinity; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D015151:Immunoblotting; D007700:Kinetics; D051379:Mice; D008969:Molecular Sequence Data; D015394:Molecular Structure; D016296:Mutagenesis; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000254:growth & development; D016133:Polymerase Chain Reaction; D011993:Recombinant Fusion Proteins; D012639:Seeds / Q000254:growth & development; D016415:Sequence Alignment; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013329:Structure-Activity Relationship; D000074405:Valosin Containing Protein
chemical_list: D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; C497351:PUX1 protein, Arabidopsis; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; D000251:Adenosine Triphosphatases; D000074405:Valosin Containing Protein