Proteins encoded by an auxin-regulated gene family of tobacco share limited but significant homology with glutathione S-transferases and one member indeed shows in vitro GST activity.
A number of cDNAs corresponding to auxin-regulated mRNAs have been isolated from tobacco and found to be encoded by a multigene family consisting of three subfamilies. Homologous proteins have been isolated independently from soybean and potato. Here we report that the encoded proteins show a limited but significant homology to both plant and animal glutathione S-transferases (GST, EC 2.5.1.18). For the protein NT103, encoded by a member of the Nt103 subfamily, we demonstrate an in vitro GST activity. This is the first time a function is attributed to a member of this group of auxin-induced proteins or any of its homologues. The implications of this finding and the possible relationships between auxins and GSTs are discussed.
Droog
F N
FN
Institute of Molecular Plant Sciences, Leiden University, Clusius Laboratory, Leiden, Netherlands.
Hooykaas
P J
PJ
Libbenga
K R
KR
van der Zaal
E J
EJ
D000595:Amino Acid Sequence; D004137:Dinitrochlorobenzene / Q000378:metabolism; D005786:Gene Expression Regulation; D015971:Gene Expression Regulation, Enzymologic; D005982:Glutathione Transferase / Q000235:genetics* / Q000378:metabolism; D007210:Indoleacetic Acids / Q000502:physiology; D008969:Molecular Sequence Data; D005810:Multigene Family; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D010947:Plants, Toxic; D017386:Sequence Homology, Amino Acid; D014026:Nicotiana / Q000201:enzymology / Q000235:genetics*
D004137:Dinitrochlorobenzene; D007210:Indoleacetic Acids; D010940:Plant Proteins; D005982:Glutathione Transferase