NtSCP1 from tobacco is an extracellular serine carboxypeptidase III that has an impact on cell elongation.
The leaf extracellular space contains several peptidases, most of which are of unknown function. We isolated cDNAs for two extracellular serine carboxypeptidase III genes from tobacco (Nicotiana tabacum), NtSCP1 and NtSCP2, belonging to a phylogenetic clade not yet functionally characterized in plants. NtSCP1 and NtSCP2 are orthologs derived from the two ancestors of tobacco. Reverse transcription-polymerase chain reaction analysis showed that NtSCP1 and NtSCP2 are expressed in root, stem, leaf, and flower tissues. Expression analysis of the β-glucuronidase reporter gene fused to the NtSCP1 transcription promoter region confirmed this expression profile. Western blotting of NtSCP1 and expression of an NtSCP1-green fluorescent protein fusion protein showed that the protein is located in the extracellular space of tobacco leaves and culture cells. Purified His-tagged NtSCP1 had carboxypeptidase activity in vitro. Transgenic tobacco plants overexpressing NtSCP1 showed a reduced flower length due to a decrease in cell size. Etiolated seedlings of these transgenic plants had shorter hypocotyls. These data provide support for a role of an extracellular type III carboxypeptidase in the control of cell elongation.
Institut des Sciences de la Vie, University of Louvain, 1348 Louvain-la-Neuve, Belgium.
Manuela Désirée
MD
Bienert
Mélanie
M
Delannoy
Catherine
C
Navarre
Marc
M
Boutry
D000595:Amino Acid Sequence; D002268:Carboxypeptidases / Q000235:genetics / Q000378:metabolism*; D049108:Cell Enlargement; D003001:Cloning, Molecular; D003470:Culture Media / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D018744:DNA, Plant / Q000235:genetics / Q000378:metabolism*; D004789:Enzyme Activation; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005110:Extracellular Space / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D035261:Plant Components, Aerial / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014026:Nicotiana / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development
D003470:Culture Media; D018076:DNA, Complementary; D018744:DNA, Plant; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D002268:Carboxypeptidases; C022633:serine carboxypeptidase