Publication: Subtilisin-like proprotein convertases (SPCs); host enzymes controlled viral protein processing and maturation
Issued Date
2014
Resource Type
Language
eng
ISSN
1906-2257
Rights
Mahidol University
Rights Holder(s)
Faculty of Veterinary Science Mahidol University
Bibliographic Citation
Journal of Applied Animal Science. Vol.7, No.1 (2014), 9-26
Suggested Citation
Kridsada Chaichoun Subtilisin-like proprotein convertases (SPCs); host enzymes controlled viral protein processing and maturation. Journal of Applied Animal Science. Vol.7, No.1 (2014), 9-26. Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/13334
Research Projects
Organizational Units
Authors
Journal Issue
JAAS Vol. 7 No. 1
(2557)
Thesis
Title
Subtilisin-like proprotein convertases (SPCs); host enzymes controlled viral protein processing and maturation
Alternative Title(s)
กลุ่มเอนไซม์ Subtilisin-like proprotein convertases (SPCs); เอนไซม์ของเซลล์โฮสต์ที่ควบคุมการตัดโปรตีนและการสมบูรณ์แบบของอนุภาคเชื้อไวรัส
Author(s)
Abstract
The cellular subtilisin-like proprotein convertases (SPCs) are responsible for virion maturation process
which occurs in secretory vesicles, primes virion maturation and viral infectivity. Eight SPCs, SPC1 (furin/PACE),
SPC2 (PC2), SPC3 (PC1/PC3), SPC4 (PACE4), SPC5 (PC4), SPC6 (PC5/PC6A) and SPC7 (LPC/PC7/PC8)
and PCSK9, were identified. The consensus substrate sequence is -RX(K/R)R▼X- (X can be any amino acid, ▼
represents the cleavage site). The conformational change of viral proteins can be triggered by a low pH in the
endosomes, as in the case of influenza virus, or by the interaction with a secondary receptor protein at the cell
surface, as the case of HIV. In flaviviruses, the functional roles of charged residues locate to the SPC consensus
sequence in cleavage site of prM protein and provide cleavability affect to virus replication. Changes in the
prM-cleavage level were associated with altered proportions of extracellular virions and subviral particles.
The hemagglutinin (HA) protein is a critical determinant of the pathogenicity of avian influenza viruses, with a
clear link between HA cleavability and virulence. The highly pathogenic avian influenza virus, in which
contain high numbers of basic amino acid sequence at the HA cleavage site, can be converted to low numbers
of basic amino acid sequence of a typical avirulent virus. The processing by SPCs is an important control
mechanism for the biological activity of viral surface proteins. The molecular mechanisms underlying the
recognition of SPCs by viral glycoproteins were described, including recent findings demonstrating differential
SPC-recognition of viral and cellular substrates. Proteolytic activation of envelope glycoproteins is necessary for
entry of viruses into the host cell and, hence, for their ability to undergo multiple replication cycles. Proteolytic
cleavage is the first step in the activation of virus fusion proteins and is followed by a conformational change
resulting in the exposure of the fusion domain. The conformational change can be triggered by a low pH in the
endosomes, or by the interaction with a secondary receptor protein at the cell surface.