A gene encoding a cysteine proteinase was iso- lated from senescent leave of cotton (Gossypium hirsutum) cv liaomian No. 9 by utilizing rapid amplification of cDNA ends polymerase chain reaction (RACE-PCR), and a set ...A gene encoding a cysteine proteinase was iso- lated from senescent leave of cotton (Gossypium hirsutum) cv liaomian No. 9 by utilizing rapid amplification of cDNA ends polymerase chain reaction (RACE-PCR), and a set of con- sensus oligonucleotide primers was designed to anneal the conserved sequences of plant cysteine protease genes. The cDNA, which designated Ghcysp gene, contained 1368 bp terminating in a poly(A)+ trail, and included a putative 5 (98 bp) and a 3 (235 bp) non-coding region. The opening reading frame (ORF) encodes polypeptide 344 amino acids with the predicted molecular mass of 37.88 kD and theoretical pI of 4.80. A comparison of the deduced amino acid sequence with the sequence in the GenBank database has shown consider- able sequence similarity to a novel family of plant cysteine proteases. This putative cotton Ghcysp protein shows from 67% to 82% identity to the other plants. All of them share catalytic triad of residues, which are highly conserved in three regions. Hydropaths analysis of the amino acid se- quence shows that the Ghcysp is a potential membrane pro- tein and localizes to the vacuole, which has a transmembrane helix between resides 7 —25. A characteristic feature of Ghcysp is the presence of a putative vacuole-targeting signal peptide of 19-amino acid residues at the N-terminal region. The expression of Ghcysp gene was determined using north- ern blot analysis. The Ghcysp mRNA levels are high in de- velopment senescent leaf but below the limit of detection in senescent root, hypocotyl, faded flower, 6 d post anthesis ovule, and young leaf.展开更多
文摘A gene encoding a cysteine proteinase was iso- lated from senescent leave of cotton (Gossypium hirsutum) cv liaomian No. 9 by utilizing rapid amplification of cDNA ends polymerase chain reaction (RACE-PCR), and a set of con- sensus oligonucleotide primers was designed to anneal the conserved sequences of plant cysteine protease genes. The cDNA, which designated Ghcysp gene, contained 1368 bp terminating in a poly(A)+ trail, and included a putative 5 (98 bp) and a 3 (235 bp) non-coding region. The opening reading frame (ORF) encodes polypeptide 344 amino acids with the predicted molecular mass of 37.88 kD and theoretical pI of 4.80. A comparison of the deduced amino acid sequence with the sequence in the GenBank database has shown consider- able sequence similarity to a novel family of plant cysteine proteases. This putative cotton Ghcysp protein shows from 67% to 82% identity to the other plants. All of them share catalytic triad of residues, which are highly conserved in three regions. Hydropaths analysis of the amino acid se- quence shows that the Ghcysp is a potential membrane pro- tein and localizes to the vacuole, which has a transmembrane helix between resides 7 —25. A characteristic feature of Ghcysp is the presence of a putative vacuole-targeting signal peptide of 19-amino acid residues at the N-terminal region. The expression of Ghcysp gene was determined using north- ern blot analysis. The Ghcysp mRNA levels are high in de- velopment senescent leaf but below the limit of detection in senescent root, hypocotyl, faded flower, 6 d post anthesis ovule, and young leaf.
