The first characterization of a cystatin and a cathepsin L-like peptidase from Aedes aegypti and their possible role in DENV infection by the modulation of apoptosis
Article
Oliveira, FAA, Buri, MV, Rodriguez, BL et al. (2020). The first characterization of a cystatin and a cathepsin L-like peptidase from Aedes aegypti and their possible role in DENV infection by the modulation of apoptosis
. INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES, 146 141-149. 10.1016/j.ijbiomac.2019.12.010
Oliveira, FAA, Buri, MV, Rodriguez, BL et al. (2020). The first characterization of a cystatin and a cathepsin L-like peptidase from Aedes aegypti and their possible role in DENV infection by the modulation of apoptosis
. INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES, 146 141-149. 10.1016/j.ijbiomac.2019.12.010
Recently, a salivary gland transcriptome study demonstrated that the transcripts of a putative cystatin gene (SeqID AAEL013287; Aacystatins) from Aedes aegypti were increased in DENV2-infected mosquitoes and that silencing of the Aacystatin gene resulted in an increase in DENV titres. In this work, Aacystatin was biochemically characterized; the purified recombinant inhibitor was able to inhibit typical cysteine proteases with a Ki in the nM range. Pulldown assays using Aag2 cell extracts identified a cathepsin L-like peptidase (AaCatL) as a possible target of Aacystatin. Purified recombinant AaCatL had an optimal pH of 5.0 and displayed a preference for Leu, Val and Phe residues at P2, which is common for other cathepsin L-like peptidases. Transcription analysis of Aacystatin and AaCatL in the salivary glands and midgut of DENV2-infected mosquitoes revealed a negative correlation between DENV2 titres and levels of the inhibitor and peptidase, suggesting their involvement in DENV2-mosquito interactions. Considering that apoptosis may play an important role during viral infections, the possible involvement of Aacystatin in staurosporine-induced apoptosis in Aag2 cells was investigated; the results showed higher expression of the inhibitor in treated cells; moreover, pre incubation with rAacystatin was able to increase Aag2 cell viability.
