Reaching the melting point: Degradative enzymes and protease inhibitors involved in baculovirus infection and dissemination

Abstract

Baculovirus infection of a host insect involves several steps, beginning with initiation of virus infection in the midgut, followed by dissemination of infection from the midgut to other tissues in the insect, and finally culminating in “melting” or liquefaction of the host, which allows for horizontal spread of infection to other insects. While all of the viral gene products are involved in ultimately reaching this dramatic infection endpoint, this review focuses on two particular types of baculovirus-encoded proteins: degradative enzymes and protease inhibitors. Neither of these types of proteins is commonly found in other virus families, but they both play important roles in baculovirus infection. The types of degradative enzymes and protease inhibitors encoded by baculoviruses are discussed, as are the roles of these proteins in the infection process.

Expression of the Cydia pomonella granulovirus matrix metalloprotease enhances Autographa californica multiple nucleopolyhedrovirus virulence and can partially substitute for viral cathepsin

“…To date, only one baculovirus encodes a serpin gene (Rohrmann et al, 2013), and it is functional (Ardisson-Araujo et al, 2015). Thus, it is not clear if there are functional relationships between MMPs, cathepsins, and serpins (Ishimwe et al, 2015). …”

“…These results show that a number of enzymes, their interplay, concentrations, and cellular localization are all important for efficient virus dispersal. Baculoviruses encode a number of degradative enzymes that may optimize virus infection and dispersal (Ishimwe et al, 2015). …”

A tale of two transcriptomic responses in agricultural pests via host defenses and viral replication

“…The co-expressed viral genes chitinase (Ac126) and cathepsin (Ac127) are required for the liquefaction of hosts in the late stage of infection [105,106]. Viral chitinases act on degrading the host chitins and cathepsins are broad-spectrum proteases that degrade host tissue [107]. Both Ac126 (found at RPKM of 540 in S. frugiperda and 1227 in T. ni) and Ac127 (found at RPKM of 236 in S. frugiperda and 494 in T. ni) were highly exprssed in the infected samples in our study (Figure 5b and Supplementary Table 6).…”

Основные Структурные Типы Ингибиторов Матриксных Металлопротеиназ

“…Êàòàëèòè÷åñêèé ó÷àñòîê ÌÌÏ õàðàêòåðèçóåòñÿ íà-ëè÷èåì êîíñåðâàòèâíîãî öèíê-ñâÿçûâàþùåãî ó÷àñòêà, ñîäåðaeàùåãî 3 îñòàòêà ãèñòèäèíà [9].…”