Premium
Subcellular localization of host and viral proteins associated with tobamovirus RNA replication
Author(s) -
Hagiwara Yuka,
Komoda Keisuke,
Yamanaka Takuya,
Tamai Atsushi,
Meshi Tetsuo,
Funada Ryo,
Tsuchiya Tomohiro,
Naito Satoshi,
Ishikawa Masayuki
Publication year - 2003
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/cdg033
Subject(s) - library science , agriculture , graduate students , biology , sociology , ecology , pedagogy , computer science
Arabidopsis TOM1 (AtTOM1) and TOM2A (AtTOM2A) are integral membrane proteins genetically identified to be necessary for efficient intracellular multiplication of tobamoviruses. AtTOM1 interacts with the helicase domain polypeptide of tobamovirus‐encoded replication proteins and with AtTOM2A, suggesting that both AtTOM1 and AtTOM2A are integral components of the tobamovirus replication complex. We show here that AtTOM1 and AtTOM2A proteins tagged with green fluorescent protein (GFP) are targeted to the vacuolar membrane (tonoplast)‐like structures in plant cells. In subcellular fractionation analyses, GFP–AtTOM2A, AtTOM2A and its tobacco homolog NtTOM2A were predominantly fractionated to low‐density tonoplast‐rich fractions, whereas AtTOM1–GFP, AtTOM1 and its tobacco homolog NtTOM1 were distributed mainly into the tonoplast‐rich fractions and partially into higher‐buoyant‐density fractions containing membranes from several other organelles. The tobamovirus‐encoded replication proteins were co‐fractionated with both NtTOM1 and viral RNA‐dependent RNA polymerase activity. The replication proteins were also found in the fractions containing non‐membrane‐bound proteins, but neither NtTOM1 nor the polymerase activity was detected there. These observations suggest that the formation of tobamoviral RNA replication complex occurs on TOM1‐containing membranes and is facilitated by TOM2A.