The gene encoding T protein of the glycine decarboxylase complex involved in the mitochondrial step of the photorespiratory pathway in plants exhibits features of light-induced genes.
We have isolated and characterized a genomic clone encoding the 41 kDa monomer T-protein. This gene called gdcT spans approximately 3 kbp and is composed of four exons interrupted by three introns (321, 691 and 114 bp). The splice sites for donor and acceptor are in agreement with the canonical GT/AG rule. Primer extension strongly suggests the presence of two major transcription start sites. The first transcription start site around 43 bases downstream of a putative TATA box was assigned the +1 position. The second (+31) is not correlated with a putative TATA box, but revealed a pyrimidine-rich region which is very similar to the initiator element. Sequence analysis of the 5'-upstream region of the gene reveals three consensus regions found in the nuclear genes encoding the chloroplastic proteins of ribulose-1,5-bisphosphate carboxylase (rbcS) and the chlorophyll a/b-binding protein (cab) such as an AT-rich sequence localized at -539 to -530, a box II core sequence GGTTAA (-123 to -118) and between -364 and -354 a tandem GATA motif. These elements are known to be involved respectively in the regulation of light-responsiveness and cell-type specificity expression of plant genes. Gel shift assays indicate that the box II core sequence could bind protein nuclear factors similar to the trans-acting factor which interact with corresponding promoter region of rbcS gene.
Vauclare
P
P
Laboratoire de Physiologie Cellulaire Végétale, CEA, URA CNRS 576, Département de Biologie Moléculaire et Structurale PVC, CEA Grenoble, France.
Macherel
D
D
Douce
R
R
Bourguignon
J
J
D000594:Amino Acid Oxidoreductases / Q000235:genetics*; D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D018744:DNA, Plant / Q000378:metabolism; D005091:Exons / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects; D017343:Genes, Plant / Q000235:genetics*; D050959:Glycine Decarboxylase Complex; D050841:Glycine Dehydrogenase (Decarboxylating); D007438:Introns / Q000235:genetics; D008027:Light; D008969:Molecular Sequence Data; D018532:Pisum sativum / Q000201:enzymology / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D017422:Sequence Analysis, DNA; D015534:Trans-Activators / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics
D018744:DNA, Plant; D015534:Trans-Activators; D000594:Amino Acid Oxidoreductases; D050959:Glycine Decarboxylase Complex; D050841:Glycine Dehydrogenase (Decarboxylating)