Standard name Systematic name Name description Description
SKI7 YOR076C GTP-binding protein that couples the Ski complex and exosome GTP-binding protein that couples the Ski complex and exosome; putative pseudo-translational GTPase involved in 3'-to-5' mRNA decay pathway; interacts with both the cytoplasmic exosome and the Ski complex; eRF3-like domain targets nonstop mRNA for degradation; null mutants have a superkiller phenotype; SKI7 has a paralog, HBS1, that arose from the whole genome duplication
Visualize the interactome of SKI7
Links to external databases:
SGD   |   KEGG   |  

Cell cycle phase and timing of transcription peak

Cell cycle phase Time (min)

CYCLoPs localization & abundance

WT1 WT2 WT3
Cytoplasm 0.944 0.947 0.985
Mito 0.063 0.073 NaN

GFP localization & abundance

GFP localization GFP abundance
ambiguous 233

GO term count

Metabolism Cell cycle Cell division Signal transduction DNA replication
SKI7 10 0 0 0 0

List of interactors

Use the search utility to find the interactor you are looking for. By clicking the column headers the table will be sorted on that column. Use shift+click to sort on multiple columns. Default sorting is on number of experiments, number of unique methods and the number of publications, and alphabetical on standard name, in that order.
Standard name Systematic name Name description Type #Experiments #Methods #Publications Evidence
CSL4 YNL232W Exosome non-catalytic core component physical 10 4 9 Affinity Capture-MS, Affinity Capture-MS, Affinity Capture-MS, Affinity Capture-MS, Affinity Capture-MS, PCA, Affinity Capture-MS, Reconstituted Complex, Affinity Capture-Western, Affinity Capture-MS
RRP46 YGR095C Exosome non-catalytic core component physical 9 4 9 Affinity Capture-MS, Affinity Capture-MS, Affinity Capture-MS, Affinity Capture-MS, Affinity Capture-MS, Affinity Capture-MS, Reconstituted Complex, Affinity Capture-Western, Co-purification
SKI6 YGR195W Exosome non-catalytic core component physical 9 3 8 Affinity Capture-MS, Affinity Capture-Western, Affinity Capture-MS, Affinity Capture-MS, Affinity Capture-MS, Affinity Capture-MS, Affinity Capture-MS, Reconstituted Complex, Affinity Capture-Western
DIS3 YOL021C Exosome core complex catalytic subunit physical 8 3 8 Affinity Capture-MS, Affinity Capture-MS, Affinity Capture-MS, Affinity Capture-MS, Affinity Capture-MS, Affinity Capture-MS, Reconstituted Complex, Affinity Capture-Western
RRP45 YDR280W Exosome non-catalytic core component physical 8 3 7 Affinity Capture-MS, Affinity Capture-MS, Affinity Capture-MS, Affinity Capture-MS, Affinity Capture-MS, Affinity Capture-MS, Reconstituted Complex, Affinity Capture-Western
RRP4 YHR069C Exosome non-catalytic core component physical 6 3 6 Affinity Capture-Western, Affinity Capture-MS, Affinity Capture-MS, Affinity Capture-MS, Reconstituted Complex, Affinity Capture-Western
RRP43 YCR035C Exosome non-catalytic core component physical 6 3 6 Affinity Capture-MS, Affinity Capture-MS, Affinity Capture-MS, Reconstituted Complex, Affinity Capture-Western, Affinity Capture-MS
RRP42 YDL111C Exosome non-catalytic core component physical 6 3 6 Affinity Capture-MS, Affinity Capture-MS, Affinity Capture-MS, Affinity Capture-MS, Reconstituted Complex, Affinity Capture-Western
XRN1 YGL173C Evolutionarily-conserved 5'-3' exonuclease genetic 6 3 6 Synthetic Growth Defect, Negative Genetic, Negative Genetic, Synthetic Lethality, Negative Genetic, Synthetic Lethality
RRP40 YOL142W Exosome non-catalytic core component physical 6 3 5 Affinity Capture-MS, Affinity Capture-MS, Affinity Capture-MS, Affinity Capture-MS, Reconstituted Complex, Affinity Capture-Western
DOM34 YNL001W Protein that facilitates ribosomal subunit dissociation genetic 6 3 4 Synthetic Growth Defect, Synthetic Growth Defect, Synthetic Growth Defect, Phenotypic Enhancement, Phenotypic Suppression, Phenotypic Enhancement
LSM1 YJL124C Lsm (Like Sm) protein genetic 6 1 4 Negative Genetic, Negative Genetic, Negative Genetic, Negative Genetic, Negative Genetic, Negative Genetic
MTR3 YGR158C Exosome non-catalytic core component physical 5 3 5 Affinity Capture-MS, Affinity Capture-MS, Affinity Capture-MS, Reconstituted Complex, Affinity Capture-Western
PAT1 YCR077C Deadenylation-dependent mRNA-decapping factor genetic 5 1 3 Negative Genetic, Negative Genetic, Negative Genetic, Negative Genetic, Negative Genetic
DCP1 YOL149W Subunit of the Dcp1p-Dcp2p decapping enzyme complex genetic 4 3 4 Synthetic Lethality, Synthetic Growth Defect, Synthetic Lethality, Negative Genetic
SKI8 YGL213C Ski complex component and WD-repeat protein physical 4 2 4 Affinity Capture-Western, Affinity Capture-Western, Reconstituted Complex, Reconstituted Complex
HBS1 YKR084C GTPase with similarity to translation release factors genetic 4 2 4 Phenotypic Enhancement, Phenotypic Enhancement, Synthetic Growth Defect, Phenotypic Enhancement
RRP6 YOR001W Nuclear exosome exonuclease component physical 4 3 3 Affinity Capture-MS, Reconstituted Complex, Affinity Capture-Western, Affinity Capture-Western
ASC1 YMR116C G-protein beta subunit and guanine dissociation inhibitor for Gpa2p genetic 4 1 3 Negative Genetic, Negative Genetic, Negative Genetic, Negative Genetic
SKI3 YPR189W Ski complex component and TPR protein physical 3 2 3 Affinity Capture-Western, Reconstituted Complex, Reconstituted Complex
SKI2 YLR398C Ski complex component and putative RNA helicase physical 3 2 3 Affinity Capture-Western, Reconstituted Complex, Reconstituted Complex
RIA1 YNL163C Cytoplasmic GTPase/eEF2-like factor involved in ribosomal biogenesis genetic 3 2 3 Negative Genetic, Synthetic Growth Defect, Negative Genetic
NPL3 YDR432W RNA-binding protein genetic 3 3 2 Negative Genetic, Synthetic Rescue, Synthetic Growth Defect
RKR1 YMR247C RING domain E3 ubiquitin ligase genetic 3 2 2 Phenotypic Enhancement, Synthetic Growth Defect, Phenotypic Enhancement
NUC1 YJL208C Major mitochondrial nuclease genetic 3 1 2 Negative Genetic, Negative Genetic, Negative Genetic
LAC1 YKL008C Ceramide synthase component genetic 3 1 2 Negative Genetic, Negative Genetic, Negative Genetic
RMD1 YDL001W Cytoplasmic protein required for sporulation genetic 3 1 2 Negative Genetic, Negative Genetic, Negative Genetic
CHL1 YPL008W Probable DNA helicase genetic 3 1 2 Negative Genetic, Negative Genetic, Negative Genetic
UBI4 YLL039C Ubiquitin genetic 3 1 2 Negative Genetic, Negative Genetic, Negative Genetic
VMS1 YDR049W Peptidyl-tRNA hydrolase that releases stalled peptides from ribosomes, genetic 3 1 2 Negative Genetic, Negative Genetic, Negative Genetic
CPR7 YJR032W Peptidyl-prolyl cis-trans isomerase (cyclophilin) genetic 3 1 2 Negative Genetic, Negative Genetic, Negative Genetic
BCH2 YKR027W Member of the ChAPs (Chs5p-Arf1p-binding proteins) family genetic 3 1 2 Negative Genetic, Negative Genetic, Negative Genetic
RPL24A YGL031C Ribosomal 60S subunit protein L24A genetic 3 1 2 Negative Genetic, Negative Genetic, Negative Genetic
MUP1 YGR055W High affinity methionine permease genetic 3 1 2 Negative Genetic, Negative Genetic, Negative Genetic
DCP2 YNL118C Catalytic subunit of Dcp1p-Dcp2p decapping enzyme complex genetic 2 2 2 Synthetic Lethality, Negative Genetic
SDO1 YLR022C Guanine nucleotide exchange factor (GEF) for Ria1p genetic 2 2 2 Synthetic Growth Defect, Negative Genetic
FKH1 YIL131C Forkhead family transcription factor regulation 2 1 2 chromatin immunoprecipitation-chip evidence, chromatin immunoprecipitation-chip evidence
RPN12 YFR052W Subunit of the 19S regulatory particle of the 26S proteasome lid genetic 2 1 2 Negative Genetic, Negative Genetic
DHH1 YDL160C Cytoplasmic DEAD-box helicase and mRNA decapping activator physical 2 1 2 Affinity Capture-RNA, Affinity Capture-RNA
ANP1 YEL036C Subunit of the alpha-1,6 mannosyltransferase complex genetic 2 1 2 Positive Genetic, Positive Genetic
SAM1 YLR180W S-adenosylmethionine synthetase genetic 2 1 2 Negative Genetic, Negative Genetic
MSH4 YFL003C Protein involved in meiotic recombination genetic 2 1 2 Negative Genetic, Negative Genetic
HSE1 YHL002W Subunit of the endosomal Vps27p-Hse1p complex physical 2 1 2 Two-hybrid, Two-hybrid
LSM8 YJR022W Lsm (Like Sm) protein physical 2 1 2 Two-hybrid, Two-hybrid
GCR2 YNL199C Transcriptional activator of genes involved in glycolysis genetic 2 1 2 Negative Genetic, Negative Genetic
ATG1 YGL180W Protein serine/threonine kinase genetic 2 1 2 Negative Genetic, Negative Genetic
SNF6 YHL025W Subunit of the SWI/SNF chromatin remodeling complex genetic 2 1 2 Negative Genetic, Negative Genetic
STE24 YJR117W Highly conserved zinc metalloprotease genetic 2 1 2 Negative Genetic, Negative Genetic
YNL058C YNL058C Putative protein of unknown function genetic 2 1 2 Negative Genetic, Negative Genetic
LRS4 YDR439W Nucleolar protein that forms a complex with Csm1p genetic 2 1 2 Positive Genetic, Positive Genetic
CPS1 YJL172W Vacuolar carboxypeptidase S genetic 2 1 2 Negative Genetic, Negative Genetic
RPP1A YDL081C Ribosomal stalk protein P1 alpha genetic 2 1 2 Negative Genetic, Negative Genetic
SAC1 YKL212W Phosphatidylinositol phosphate phosphatase genetic 2 1 2 Negative Genetic, Negative Genetic
PDR15 YDR406W Plasma membrane ATP binding cassette (ABC) transporter genetic 2 1 2 Negative Genetic, Negative Genetic
QRI1 YDL103C UDP-N-acetylglucosamine pyrophosphorylase genetic 2 1 2 Negative Genetic, Negative Genetic
SDH8 YBR269C Protein required for assembly of succinate dehydrogenase genetic 2 1 2 Negative Genetic, Negative Genetic
MET22 YOL064C Bisphosphate-3'-nucleotidase genetic 2 1 2 Negative Genetic, Negative Genetic
LCB2 YDR062W Component of serine palmitoyltransferase genetic 2 2 1 Positive Genetic, Negative Genetic
LSM6 YDR378C Lsm (Like Sm) protein genetic 2 1 1 Negative Genetic, Negative Genetic
AIM3 YBR108W Protein that inhibits barbed-end actin filament elongation genetic 2 1 1 Positive Genetic, Positive Genetic
OCA2 YNL056W Protein of unknown function genetic 2 1 1 Negative Genetic, Negative Genetic
UBA3 YPR066W Protein that activates Rub1p (NEDD8) before neddylation genetic 2 1 1 Negative Genetic, Negative Genetic
OPI3 YJR073C Methylene-fatty-acyl-phospholipid synthase genetic 2 1 1 Negative Genetic, Negative Genetic
MCT1 YOR221C Predicted malonyl-CoA:ACP transferase genetic 2 1 1 Negative Genetic, Negative Genetic
RPS30A YLR287C-A Protein component of the small (40S) ribosomal subunit genetic 2 1 1 Negative Genetic, Negative Genetic
RGR1 YLR071C Subunit of the RNA polymerase II mediator complex regulation 1 1 1 chromatin immunoprecipitation-chip evidence
STP1 YDR463W Transcription factor regulation 1 1 1 chromatin immunoprecipitation-chip evidence
REB1 YBR049C RNA polymerase I enhancer binding protein regulation 1 1 1 chromatin immunoprecipitation-chip evidence
STB1 YNL309W Protein with role in regulation of MBF-specific transcription at Start regulation 1 1 1 DNA to cDNA expression microarray evidence
YAP5 YIR018W Basic leucine zipper (bZIP) iron-sensing transcription factor regulation 1 1 1 DNA to cDNA expression microarray evidence
RAD53 YPL153C DNA damage response kinase regulation 1 1 1 protein kinase assay evidence
AME1 YBR211C Essential kinetochore protein associated with microtubules and SPBs genetic 1 1 1 Positive Genetic
DED81 YHR019C Cytosolic asparaginyl-tRNA synthetase genetic 1 1 1 Positive Genetic
RPL17A YKL180W Ribosomal 60S subunit protein L17A genetic 1 1 1 Negative Genetic
ADH1 YOL086C Alcohol dehydrogenase genetic 1 1 1 Negative Genetic
POP8 YBL018C Subunit of both RNase MRP and nuclear RNase P genetic 1 1 1 Positive Genetic
BRR2 YER172C RNA-dependent ATPase RNA helicase (DEIH box) genetic 1 1 1 Negative Genetic
LTO1 YNL260C Substrate-specific adaptor protein involved in apo-Rli1p maturation genetic 1 1 1 Negative Genetic
RRP7 YCL031C Essential protein involved in rRNA processing and ribosome biogenesis genetic 1 1 1 Positive Genetic
MTR4 YJL050W RNA duplex-sensing translocase genetic 1 1 1 Negative Genetic
LSM3 YLR438C-A Lsm (Like Sm) protein genetic 1 1 1 Negative Genetic
NOP1 YDL014W Histone glutamine methyltransferase, modifies H2A at Q105 in nucleolus genetic 1 1 1 Positive Genetic
GCD11 YER025W Gamma subunit of the translation initiation factor eIF2 genetic 1 1 1 Positive Genetic
RSC2 YLR357W Component of the RSC chromatin remodeling complex genetic 1 1 1 Positive Genetic
RPN11 YFR004W Metalloprotease subunit of 19S regulatory particle genetic 1 1 1 Negative Genetic
RPN5 YDL147W Subunit of the CSN and 26S proteasome lid complexes genetic 1 1 1 Negative Genetic
ACT1 YFL039C Actin, structural protein in cytoskeleton genetic 1 1 1 Negative Genetic
CCR4 YAL021C Component of the CCR4-NOT transcriptional complex physical 1 1 1 Affinity Capture-RNA
LSG1 YGL099W Putative GTPase involved in 60S ribosomal subunit biogenesis genetic 1 1 1 Negative Genetic
NAB2 YGL122C Nuclear polyadenylated RNA-binding protein physical 1 1 1 Affinity Capture-RNA
NAM7 YMR080C ATP-dependent RNA helicase of the SFI superfamily physical 1 1 1 Reconstituted Complex
CAF130 YGR134W Subunit of the CCR4-NOT transcriptional regulatory complex genetic 1 1 1 Negative Genetic
ISW1 YBR245C ATPase subunit of imitation-switch (ISWI) class chromatin remodelers physical 1 1 1 Affinity Capture-RNA
CLU1 YMR012W Subunit of the eukaryotic translation initiation factor 3 (eIF3) genetic 1 1 1 Positive Genetic
KRR1 YCL059C Nucleolar protein required for rRNA synthesis and ribosomal assembly genetic 1 1 1 Positive Genetic
END3 YNL084C EH domain-containing protein involved in endocytosis genetic 1 1 1 Negative Genetic
LSM7 YNL147W Lsm (Like Sm) protein genetic 1 1 1 Negative Genetic
HSC82 YMR186W Cytoplasmic chaperone of the Hsp90 family genetic 1 1 1 Synthetic Growth Defect
MRPL10 YNL284C Mitochondrial ribosomal protein of the large subunit genetic 1 1 1 Negative Genetic
ORC2 YBR060C Subunit of the origin recognition complex (ORC) genetic 1 1 1 Positive Genetic
HSP82 YPL240C Hsp90 chaperone genetic 1 1 1 Synthetic Growth Defect
PRE4 YFR050C Beta 7 subunit of the 20S proteasome genetic 1 1 1 Negative Genetic
PUB1 YNL016W Poly (A)+ RNA-binding protein physical 1 1 1 Affinity Capture-MS
PRE9 YGR135W Alpha 3 subunit of the 20S proteasome genetic 1 1 1 Phenotypic Enhancement
MKT1 YNL085W Protein similar to nucleases that forms a complex with Pbp1p genetic 1 1 1 Synthetic Rescue
SAP30 YMR263W Component of Rpd3L histone deacetylase complex genetic 1 1 1 Negative Genetic
CCT6 YDR188W Subunit of the cytosolic chaperonin Cct ring complex genetic 1 1 1 Positive Genetic
HEK2 YBL032W RNA binding protein involved in asymmetric localization of ASH1 mRNA physical 1 1 1 Affinity Capture-RNA
CDC13 YDL220C Single stranded DNA-binding protein found at TG1-3 telomere G-tails genetic 1 1 1 Synthetic Rescue
NOP6 YDL213C rRNA-binding protein required for 40S ribosomal subunit biogenesis genetic 1 1 1 Negative Genetic
FHL1 YPR104C Regulator of ribosomal protein (RP) transcription genetic 1 1 1 Negative Genetic
RSP5 YER125W NEDD4 family E3 ubiquitin ligase genetic 1 1 1 Negative Genetic
GPN3 YLR243W Putative GTPase with a role in biogenesis of RNA pol II and polIII genetic 1 1 1 Positive Genetic
ERG6 YML008C Delta(24)-sterol C-methyltransferase genetic 1 1 1 Negative Genetic
NOP53 YPL146C Nucleolar protein genetic 1 1 1 Negative Genetic
PAP2 YOL115W Non-canonical poly(A) polymerase genetic 1 1 1 Negative Genetic
EAP1 YKL204W eIF4E-associated protein, competes with eIF4G for binding to eIF4E genetic 1 1 1 Negative Genetic
BIR1 YJR089W Subunit of chromosomal passenger complex (CPC) genetic 1 1 1 Positive Genetic
CLN3 YAL040C G1 cyclin involved in cell cycle progression genetic 1 1 1 Negative Genetic
NUP57 YGR119C FG-nucleoporin component of central core of the nuclear pore complex genetic 1 1 1 Positive Genetic
CET1 YPL228W RNA 5'-triphosphatase involved in mRNA 5' capping genetic 1 1 1 Positive Genetic
CSE4 YKL049C Centromeric histone H3-like protein genetic 1 1 1 Positive Genetic
RAP1 YNL216W Essential DNA-binding transcription regulator that binds many loci genetic 1 1 1 Positive Genetic
TAD2 YJL035C Subunit of tRNA-specific adenosine-34 deaminase genetic 1 1 1 Negative Genetic
SRP1 YNL189W Karyopherin alpha homolog genetic 1 1 1 Negative Genetic
SNT309 YPR101W Member of the NineTeen Complex (NTC) genetic 1 1 1 Negative Genetic
TIF4631 YGR162W Translation initiation factor eIF4G and scaffold protein genetic 1 1 1 Positive Genetic
YGK3 YOL128C Protein kinase related to mammalian GSK-3 glycogen synthase kinases genetic 1 1 1 Negative Genetic
SUP35 YDR172W Translation termination factor eRF3 genetic 1 1 1 Synthetic Rescue
SRS2 YJL092W DNA helicase and DNA-dependent ATPase genetic 1 1 1 Dosage Lethality
ZUO1 YGR285C Ribosome-associated chaperone genetic 1 1 1 Phenotypic Enhancement
YOR1 YGR281W Plasma membrane ATP-binding cassette (ABC) transporter genetic 1 1 1 Positive Genetic
SPC110 YDR356W Inner plaque spindle pole body (SPB) component genetic 1 1 1 Synthetic Growth Defect
TAF12 YDR145W Subunit (61/68 kDa) of TFIID and SAGA complexes genetic 1 1 1 Positive Genetic
TIM54 YJL054W Component of the mitochondrial TIM22 complex genetic 1 1 1 Positive Genetic
SSC1 YJR045C Hsp70 family ATPase genetic 1 1 1 Positive Genetic
TAH11 YJR046W DNA replication licensing factor genetic 1 1 1 Positive Genetic
SMD2 YLR275W Core Sm protein Sm D2 genetic 1 1 1 Positive Genetic
SMX3 YPR182W Core Sm protein Sm F genetic 1 1 1 Positive Genetic
THS1 YIL078W Threonyl-tRNA synthetase genetic 1 1 1 Negative Genetic
YGL188C-A YGL188C-A Putative protein of unknown function genetic 1 1 1 Negative Genetic
YVH1 YIR026C Dual specificity protein phosphatase genetic 1 1 1 Negative Genetic
VRP1 YLR337C Verprolin, proline-rich actin-associated protein genetic 1 1 1 Negative Genetic
SLA2 YNL243W Adaptor protein that links actin to clathrin and endocytosis genetic 1 1 1 Negative Genetic
TPS2 YDR074W Phosphatase subunit of the trehalose-6-P synthase/phosphatase complex genetic 1 1 1 Negative Genetic
YGR035C YGR035C Putative protein of unknown function, potential Cdc28p substrate genetic 1 1 1 Negative Genetic
STB5 YHR178W Transcription factor genetic 1 1 1 Negative Genetic
SPE1 YKL184W Ornithine decarboxylase genetic 1 1 1 Negative Genetic
UBX2 YML013W Bridging factor involved in ER-associated protein degradation (ERAD) genetic 1 1 1 Negative Genetic
NMD2 YHR077C Protein involved in the nonsense-mediated mRNA decay (NMD) pathway physical 1 1 1 Affinity Capture-Western
HSF1 YGL073W Trimeric heat shock transcription factor genetic 1 1 1 Negative Genetic
GLN3 YER040W Transcriptional activator in nitrogen catabolite repression system genetic 1 1 1 Negative Genetic
ESC2 YDR363W Sumo-like domain protein genetic 1 1 1 Synthetic Lethality
CLA4 YNL298W Cdc42p-activated signal transducing kinase genetic 1 1 1 Positive Genetic
MNN11 YJL183W Subunit of a Golgi mannosyltransferase complex genetic 1 1 1 Negative Genetic
RPS2 YGL123W Protein component of the small (40S) subunit genetic 1 1 1 Positive Genetic
INP51 YIL002C Phosphatidylinositol 4,5-bisphosphate 5-phosphatase genetic 1 1 1 Positive Genetic
RPL28 YGL103W Ribosomal 60S subunit protein L28 genetic 1 1 1 Negative Genetic
NOP19 YGR251W Ribosome biogenesis factor genetic 1 1 1 Positive Genetic
NDE2 YDL085W Mitochondrial external NADH dehydrogenase physical 1 1 1 Affinity Capture-MS
ABZ2 YMR289W Aminodeoxychorismate lyase (4-amino-4-deoxychorismate lyase) genetic 1 1 1 Negative Genetic
SEH1 YGL100W Subunit of the Nup84 nuclear pore and SEACAT subcomplexes genetic 1 1 1 Positive Genetic
RPL36A YMR194W Ribosomal 60S subunit protein L36A genetic 1 1 1 Negative Genetic
EOS1 YNL080C Protein involved in N-glycosylation genetic 1 1 1 Negative Genetic
POT1 YIL160C 3-ketoacyl-CoA thiolase with broad chain length specificity genetic 1 1 1 Negative Genetic
ATG15 YCR068W Phospholipase genetic 1 1 1 Negative Genetic
MRM2 YGL136C Mitochondrial 2' O-ribose methyltransferase genetic 1 1 1 Positive Genetic
PHO89 YBR296C Plasma membrane Na+/Pi cotransporter genetic 1 1 1 Phenotypic Enhancement
EMC2 YJR088C Member of conserved ER transmembrane complex genetic 1 1 1 Negative Genetic
NAR1 YNL240C Subunit of the cytosolic iron-sulfur (FeS) protein assembly machinery genetic 1 1 1 Negative Genetic
RMD9 YGL107C Mitochondrial protein that controls mitochondrial gene expression genetic 1 1 1 Negative Genetic
ADF1 YCL058W-A Transcriptional repressor encoded by the FYV5 antisense strand genetic 1 1 1 Negative Genetic
OCA6 YDR067C Cytoplasmic protein required for replication of Brome mosaic virus genetic 1 1 1 Negative Genetic