title: Proteins related to St. John's Wort p27SJ, a suppressor of HIV-1 expression, are ubiquitous in plants.
abstract: Proteins belonging to the family of DING proteins are ubiquitous in animals and several of them are associated with various diseases. Their presence in a few plant species has previously been reported and the St John's Wort DING protein was recently described as an inhibitor of HIV replication and transcription. However, data about DING protein occurrence in plants and their biochemical properties remain almost nonexistent. We describe methods for the purification of DING proteins from plants that may have general applicability since they are not dependent upon specific affinity ligands, contrary to previously described protocols. Cibacron Blue chromatography, sometimes preceded by an ion-exchange chromatographic step, is suitable for most plant extracts. DING proteins were purified from various species and cell types and their identity was confirmed immunologically and, in some cases, by N-terminal sequence analysis, indicating that they are ubiquitous in the plant kingdom. They are associated with the cell wall and sometimes secreted in the medium for in vitro grown cells. High-molecular-weight DING precursors were often observed. Internal peptides were also sequenced, as a prelude to gene cloning experiments.
authors.affiliation: School of Biological Sciences, University of Auckland, Auckland, New Zealand.
authors.forename: Tekla
authors.initials: T
authors.lastname: Perera
authors.forename: Anne
authors.initials: A
authors.lastname: Berna
authors.forename: Ken
authors.initials: K
authors.lastname: Scott
authors.forename: Christelle
authors.initials: C
authors.lastname: Lemaitre-Guillier
authors.forename: François
authors.initials: F
authors.lastname: Bernier
mesh_terms: D000595:Amino Acid Sequence; D019380:Anti-HIV Agents / Q000302:isolation & purification* / Q000494:pharmacology; D017360:Arabidopsis / Q000378:metabolism; D015153:Blotting, Western; D004591:Electrophoresis, Polyacrylamide Gel; D015967:Gene Expression Regulation, Viral / Q000187:drug effects; D015497:HIV-1 / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D006801:Humans; D020902:Hypericum / Q000378:metabolism; D027723:Ipomoea batatas / Q000378:metabolism; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D011485:Protein Binding; D011198:Solanum tuberosum / Q000378:metabolism; D014026:Nicotiana / Q000378:metabolism; D014779:Virus Replication / Q000187:drug effects
chemical_list: D019380:Anti-HIV Agents; D010940:Plant Proteins