Comparative analysis of two attacin genes from Hyphantria cunea.
A full-length clone corresponding to attacin was isolated from a cDNA library made from fat body of immunized Hyphantria cunea larvae. This newly isolated attacin B shows characteristics different from those previously reported for attacin A. The two attacin cDNAs encode precursor proteins of 233 and 248 amino acid residues, respectively. The two attacins show 45.9% identity at the amino acid level, and 35.2% identity at the nucleotide level. Attacins A and B of H. cunea show significant identities with the attacins of Lepidoptera. Attacin B is a typical glycine-rich protein, while attacin A is leucine-rich. Attacin B is expressed from last instar larvae to adult, while attacin A showed stage-specific expression during the prepupal and pupal stages. Attacins A and B are predicted to have different secondary structure in that attacin A has no tendency to form helices but attacin B contains a substantial number of helices. Attacin A is induced at a trace level in infected larvae, while attacin B is strongly induced against Gram-positive and negative bacteria, fungi, and viruses. The attacin B transcripts were detected in fat body, epidermis and hemocytes after injection with Escherichia coli, Citrobacter freundii, or Candida albicans, but not in the midgut and Malpighian tubule. Recombinant attacin A showed no antibacterial activity, while recombinant attacin B showed strong antibacterial activity in proportion to the amount of the protein injected.
Kwon
Y M
YM
Division of Applied Life Science, Gyeongsang National University, Jinju, Republic of Korea.
Kim
H J
HJ
Kim
Y I
YI
Kang
Y J
YJ
Lee
I H
IH
Jin
B R
BR
Han
Y S
YS
Cheon
H M
HM
Ha
N G
NG
Seo
S J
SJ
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002176:Candida albicans / Q000276:immunology / Q000472:pathogenicity; D016971:Citrobacter freundii / Q000276:immunology / Q000472:pathogenicity; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D004926:Escherichia coli / Q000276:immunology / Q000472:pathogenicity; D005216:Fat Body / Q000276:immunology / Q000382:microbiology; D017344:Genes, Insect; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D007814:Larva / Q000276:immunology / Q000382:microbiology; D008969:Molecular Sequence Data; D009036:Moths / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D017924:Nucleopolyhedroviruses / Q000276:immunology / Q000472:pathogenicity; D010802:Phylogeny; D017433:Protein Structure, Secondary
D017931:DNA Primers; D018076:DNA, Complementary; D019476:Insect Proteins; C039711:attacin antibacterial protein, insect