Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:3.4.23.16 (
HIV-1 protease
)
2,107
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The replication of tick-borne encephalitis virus (TBEV), like that of all flaviviruses, is absolutely dependent on proteolytic processing. Production of the mature proteins C and prM from their common precursor requires the activity of the viral NS2B/3 protease (NS2B/3(pro)) at the C-terminus of
protein C
and the host signal peptidase I (SPaseI) at the N-terminus of protein prM. Recently, we have shown in cell culture that the cleavage of
protein C
and the subsequent production of TBEV particles can be made dependent on the activity of the foot-and-mouth disease virus 3C protease, but not on the activity of the
HIV-1 protease
(HIV1(pro)) (Schrauf et al., 2012). To investigate this failure, we developed an in vitro cleavage assay to assess the two cleavage reactions performed on the C-prM precursor. Accordingly, a recombinant modular NS2B/3(pro), consisting of the protease domain of NS3 linked to the core-domain of cofactor NS2B, was expressed in E. coli and purified to homogeneity. This enzyme could cleave a C-prM protein synthesised in rabbit reticulocyte lysates. However, cleavage was only specific when protein synthesis was performed in the presence of canine pancreatic microsomal membranes and required the prevention of signal peptidase I (SPaseI) activity by lengthening the h-region of the signal peptide. The presence of membranes allowed the concentration of NS2B/3(pro) used to be reduced by 10-20 fold. Substitution of the NS2B/3(pro) cleavage motif in C-prM by a HIV-1(pro) motif inhibited NS2B/3(pro) processing in the presence of microsomal membranes but allowed cleavage by HIV-1(pro) at the C-prM junction. This system shows that processing at the C-terminus of
protein C
by the TBEV NS2B/3(pro) is highly membrane dependent and will allow the examination of how the membrane topology of
protein C
affects both SPaseI and NS2B/3(pro) processing.
...
PMID:NS2B/3 proteolysis at the C-prM junction of the tick-borne encephalitis virus polyprotein is highly membrane dependent. 2272 84
