title: Plant-specific 4/1 polypeptide interacts with an endoplasmic reticulum protein related to human BAP31.
abstract: The plant-specific 4/1 protein interacts, both in yeast two-hybrid system and in vitro, and co-localizes in plant cells with plant BAP-like protein, the orthologue of human protein BAP31. In yeast two-hybrid system, we identified a number of Nicotiana benthamiana protein interactors of Nt-4/1, the protein known to affect systemic transport of potato spindle tuber viroid. For one of these interactors, an orthologue of human B-cell receptor-associated protein 31 (BAP31) termed plant BAP-like protein (PBL), the ability to interact with Nt-4/1 was studied in greater detail. Analyses of purified proteins expressed in bacterial cells carried out in vitro with the surface plasmon resonance (SPR) spectroscopy revealed that the N. tabacum PBL (NtPBL) was able to interact with Nt-4/1 with high-affinity, and that their complex can form at physiologically relevant concentrations of both proteins. Subcellular localization studies of 4/1-GFP and NtPBL-mRFP transiently co-expressed in plant cells revealed the co-localization of the two fusion proteins in endoplasmic reticulum-associated bodies, suggesting their interaction in vivo. The N-terminal region of the Nt-4/1 protein was found to be required for the specific subcellular targeting of the protein, presumably due to a predicted amphipathic helix mediating association of the Nt-4/1 protein with cell membranes. Additionally, this region was found to contain a trans-activator domain responsible for the Nt-4/1 ability to activate transcription of a reporter gene in yeast.
authors.affiliation: Department of Virology, Biological Faculty, Moscow State University, Moscow, 119992, Russia.
authors.forename: Anna V
authors.initials: AV
authors.lastname: Pankratenko
authors.affiliation: Department of Virology, Biological Faculty, Moscow State University, Moscow, 119992, Russia.
authors.forename: Anastasia K
authors.initials: AK
authors.lastname: Atabekova
authors.affiliation: Department of Virology, Biological Faculty, Moscow State University, Moscow, 119992, Russia.
authors.forename: Ekaterina A
authors.initials: EA
authors.lastname: Lazareva
authors.affiliation: Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, 119992, Russia.
authors.forename: Viktoriia E
authors.initials: VE
authors.lastname: Baksheeva
authors.affiliation: Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, 119992, Russia.
authors.forename: Oxana A
authors.initials: OA
authors.lastname: Zhironkina
authors.affiliation: Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, 119992, Russia.
authors.forename: Evgeni Yu
authors.initials: EY
authors.lastname: Zernii
authors.affiliation: Molecular Plant Pathology Laboratory, USDA-ARS, Beltsville, MD, 20705, USA.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Owens
authors.affiliation: Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, 119992, Russia.|Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Moscow, 119991, Russia.
authors.forename: Andrey G
authors.initials: AG
authors.lastname: Solovyev
authors.affiliation: Department of Virology, Biological Faculty, Moscow State University, Moscow, 119992, Russia. morozov@genebee.msu.su.|Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, 119992, Russia. morozov@genebee.msu.su.
authors.forename: Sergey Y
authors.initials: SY
authors.lastname: Morozov
mesh_terms: D000595:Amino Acid Sequence; D002462:Cell Membrane / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D008565:Membrane Proteins / Q000378:metabolism*; D010455:Peptides / Q000378:metabolism*; D019441:Plant Epidermis / Q000166:cytology; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D013347:Subcellular Fractions / Q000378:metabolism; D020349:Surface Plasmon Resonance; D014026:Nicotiana / Q000378:metabolism*; D015533:Transcriptional Activation / Q000235:genetics; D020798:Two-Hybrid System Techniques
chemical_list: C091247:BCAP31 protein, human; D008565:Membrane Proteins; D010455:Peptides; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins
keywords: BAP31; Endoplasmic reticulum; Plant protein 4/1; Surface plasmon resonance; Transient protein expression; Yeast two-hybrid system