Isolation and characterization of a cDNA encoding a serine proteinase from the root-knot nematode Meloidogyne incognita.
This report describes the first serine proteinase gene isolated from the sedentary nematode Meloidogyne incognita. Using degenerate primers, a 1372bp cDNA encoding a chymotrypsin-like serine proteinase (Mi-ser1) was amplified from total RNA of adult females by RT-PCR and 5' and 3' rapid amplification of cDNA ends. The deduced amino acid sequence of Mi-ser1 encoded a putative signal peptide and a prodomain of 22 and 33 amino acids, respectively, and a mature proteinase of 341 amino acids with a predicted molecular mass of 37,680Da. Sequence identity with the top serine proteinases matches from the databases ranged from 23 to 27%, including sequences from insects, mammals, and other nematodes. Southern blot analysis suggested that Mi-ser1 is encoded by a single or few gene copies. The pattern of developmental expression analyzed by Northern blot and RT-PCR indicated that Mi-ser1 was transcribed mainly in females. The domain architecture composed of a single chymotrypsin-like catalytic domain and the detection of a putative signal peptide suggested a digestive role for Mi-ser1.
Fragoso
Rodrigo da Rocha
RR
EMBRAPA, Recursos Genéticos e Biotecnologia, Brasília, DF, Brazil.
Batista
João Aguiar Nogueira
JA
Neto
Osmundo Brilhante Oliveira
OB
Grossi de Sá
Maria Fátima
MF
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015139:Blotting, Southern; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000302:isolation & purification*; D018509:DNA, Helminth / Q000737:chemistry / Q000302:isolation & purification*; D020224:Expressed Sequence Tags / Q000737:chemistry; D005260:Female; D008969:Molecular Sequence Data; D021141:Nucleic Acid Amplification Techniques; D018510:RNA, Helminth / Q000737:chemistry; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D012697:Serine Endopeptidases / Q000737:chemistry / Q000235:genetics*; D014431:Tylenchoidea / Q000201:enzymology / Q000235:genetics*
D018076:DNA, Complementary; D018509:DNA, Helminth; D018510:RNA, Helminth; D012333:RNA, Messenger; D012697:Serine Endopeptidases