Characterization of the trypsin-like protease (Ha-TLP2) constitutively expressed in the integument of the cotton bollworm, Helicoverpa armigera.
Trypsins belong to the serine endoproteases. They are the most important proteases in insects because of their key roles in food digestion and zymogens activation. But there has been little study of the trypsins in the integuments of insects. In this work, we cloned a trypsin-like protease gene from Helicoverpa armigera and named it trypsin-like protease 2 (Ha-TLP2). Semi-quantitative reverse transcription PCR analysis showed that Ha-TLP2 is constitutively expressed in the integument and can be down-regulated by 20-hydroxyecdysone (20E) and up-regulated by the juvenile hormone (JH) analog methoprene. Immunohistochemistry showed that Ha-TLP2 is located not only in the epidermis, but also in new and old cuticles. Immunoblotting and gelatin-SDS-PAGE revealed that Ha-TLP2 is constitutively expressed with activity in the integument during larval feeding, molting, and metamorphosis. This evidence suggests that Ha-TLP2 is involved in the remodeling of the integument.
Liu
Yang
Y
School of Life Sciences, Shandong University, Jinan 250100, Shandong, China.
Sui
Yi-Peng
YP
Wang
Jin-Xing
JX
Zhao
Xiao-Fan
XF
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology; D015151:Immunoblotting; D019476:Insect Proteins / Q000235:genetics / Q000302:isolation & purification*; D007814:Larva / Q000201:enzymology; D008969:Molecular Sequence Data; D009036:Moths / Q000201:enzymology*; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D014357:Trypsin / Q000235:genetics / Q000302:isolation & purification*
D019476:Insect Proteins; D014357:Trypsin