title: A rapeseed cold-inducible transcript encodes a phosphoenolpyruvate carboxykinase.
abstract: We have isolated a clone corresponding to a new cold-regulated gene from a cDNA library made from rapeseed (Brassica napus cv Samourai) cold-acclimated etiolated seedlings. Sequence analysis and homology searches showed that this clone encodes a protein highly homologous to the ATP-dependent phosphoenolpyruvate carboxykinase (PEPCK; EC 4.1.1.49) from Saccharomyces cerevisiae, Trypanosoma, Rhizobium sp., and Escherichia coli; we refer to the B. napus clone as BnPEPCK. A potential ATP-binding site existing in all PEPCK proteins was also found in BnPEPCK. Although there was a basal expression of BnPEPCK in seedlings grown at control, room temperature, the steady-state level of the transcripts increased at 4 degrees C and decreased to normal levels when the seedlings were returned to control temperature (22 degrees C). Using antibodies made against a recombinant histidine-BnPEPCK fusion protein, we demonstrated that BnPEPCK protein level is correlated with the accumulation of the BnPEPCK transcript.
mesh_terms: D000064:Acclimatization; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D015153:Blotting, Western; D001937:Brassica / Q000201:enzymology*; D003080:Cold Temperature; D017931:DNA Primers; D018744:DNA, Plant / Q000302:isolation & purification; D004926:Escherichia coli / Q000201:enzymology; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D010729:Phosphoenolpyruvate Carboxykinase (GTP) / Q000096:biosynthesis* / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis / Q000302:isolation & purification; D018749:RNA, Plant / Q000032:analysis / Q000096:biosynthesis / Q000302:isolation & purification; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000302:isolation & purification; D012231:Rhizobium / Q000201:enzymology; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic; D014345:Trypanosoma / Q000201:enzymology
chemical_list: D017931:DNA Primers; D018744:DNA, Plant; D015345:Oligonucleotide Probes; D012333:RNA, Messenger; D018749:RNA, Plant; D011993:Recombinant Fusion Proteins; D010729:Phosphoenolpyruvate Carboxykinase (GTP)