Trichosanthin interacts with acidic ribosomal proteins P0 and P1 and mitotic checkpoint protein MAD2B.
Trichosanthin is a ribosome-inactivating protein with multiple pharmacological properties. By a yeast two-hybrid system, ribosomal phosphoproteins P0 and P1 and a putative mitotic checkpoint protein, MAD2B, were found to interact with an active-site mutated trichosanthin (TCS). The interactions were verified by an in vitro binding assay of recombinant wild-type TCS and target proteins. The interaction domain of P0 was mapped to amino acids 220-273, which had been previously reported to be involved in the interaction with P1 and P2 in yeast. Consistent with our previous finding that the last seven residues of TCS are not essential for an active conformation, the same deletion did not affect the interaction with P0. Our present study suggests that TCS may disrupt the binding of elongation factors to the P-complex, in addition to the well-known N-glycosidase activity for ribosome inactivation.
Department of Biochemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China.
S H
SH
Chan
F S
FS
Hung
D S
DS
Chan
P C
PC
Shaw
D001665:Binding Sites; D002460:Cell Line; D006801:Humans; D064246:Mad2 Proteins; D016297:Mutagenesis, Site-Directed; D020652:Peptide Elongation Factor 2 / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism*; D011485:Protein Binding; D011506:Proteins / Q000378:metabolism*; D012269:Ribosomal Proteins / Q000378:metabolism*; D013329:Structure-Activity Relationship; D015978:Trichosanthin / Q000235:genetics / Q000378:metabolism*; D015003:Yeasts
C120552:MAD2L2 protein, human; D064246:Mad2 Proteins; D020652:Peptide Elongation Factor 2; D010750:Phosphoproteins; D011506:Proteins; D012269:Ribosomal Proteins; C035690:ribosomal phosphoprotein P1; C054675:ribosomal protein P0; D015978:Trichosanthin