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Hymenoptera allergens
Published in Richard F. Lockey, Dennis K. Ledford, Allergens and Allergen Immunotherapy, 2020
Rafael I. Monsalve, Te Piao King, Miles Guralnick
Melittin and mastoparan are basic peptides with 26 and 14–15 residues, respectively. Both peptides are synthesized in insects as precursor molecules. The precursor is first cleaved by signal peptidase to remove the signal sequence, next cleaved by dipeptidylpeptidase IV to remove the pro sequence to yield the mature peptide [62].
Hymenoptera Allergens
Published in Richard F. Lockey, Dennis K. Ledford, Allergens and Allergen Immunotherapy, 2014
Melittin and mastoparan are basic peptides with 26 and 14–15 residues, respectively. Both peptides are synthesized in insects as precursor molecules. The precursor is cleaved first by signal peptidase to remove the signal sequence and next by dipeptidyl peptidase IV to remove the pro sequence to yield the mature peptide [43].
Rubella Virus Infections
Published in Sunit K. Singh, Daniel Růžek, Neuroviral Infections, 2013
M. Jennifer Best, Susan Reef, Liliane Grangeot-Keros
Both 40S and 24S RNA are found in RV-infected cells. The 5’ 6351 nt nonstruc-tural ORF of the 40S genomic RNA is translated to produce a 2116-amino acid polyprotein (p200; Figure 17.2). This polyprotein is cleaved by a host cell signal peptidase to give 2 nonstructural proteins, p150 and p90. The 24S subgenomic RNA produced from the 3’ structural ORF is translated to produce a 110-kDa polyprotein, which is cleaved by a host cell signalase to produce the three structural proteins (C, E2, and El; Figure 17.2). These are transported to the Golgi complex where glyco-sylation and assembly of virus particles occurs (Risco et al. 2003). Virus particles are released by budding from the plasma membrane and intracellular membranes (Figure 17.1). The cytopathic effect induced by RV in some cell cultures is due to caspase-dependent apoptosis (Cooray et al. 2003).
Recent developments in vaccines and biological therapies against Japanese encephalitis virus
Published in Expert Opinion on Biological Therapy, 2018
Recent CRISPR-based genome-wide genetic screens revealed endoplasmic reticulum-localized protein complexes involved in signal sequence recognition, N-linked glycosylation, and endoplasmic reticulum-associated degradation to be essential for viral infection [162,163]. In particular, DENV replication was nearly completely abrogated in cells deficient in the oligosaccharyltransferase (OST) complex, suggesting that this complex, which catalyzes the N-linked glycosylation of newly synthesized proteins, represents a promising target for antiviral therapy [162]. Further research showed that the small molecule aminobenzamide-sulfonamide compound NGI-1 that targets the OST complex [164] has broad-spectrum anti-flavivirus activity by blocking the viral RNA synthesis [165]. Another potential target for antiviral therapy was identified in a subset of endoplasmic reticulum-associated signal peptidase complex (SPCS) proteins, which are required for proper cleavage of the flavivirus prM and E proteins and secretion of viral particles [163]. Loss of expression of one of these proteins, SPCS1, resulted in marked reduction of replication of Flaviviridae family members, including JEV, while it had little effect on other RNA viruses [163].
In silico high throughput mutagenesis and screening of signal peptides to mitigate N-terminal heterogeneity of recombinant monoclonal antibodies
Published in mAbs, 2022
Xin Yu, Merlinda Conyne, Marc R. Lake, Karl A. Walter, Jing Min
The majority of secretory proteins in bacteria, Archaea, and Eukarya, as well as some transmembrane and intracellular proteins, carry a short peptide averaging 16–30 amino acids in length at the N-terminus.1–5 This peptide, called the signal peptide (SP), serves as the address label marking the translocation and secretion pathways of premature proteins. In mature proteins, SPs are cleaved by one of the three types of signal peptidase (SPase) – type I, II, and IV.6 SPases bind primarily to the last three to seven residues located at the C-terminus of the SP (also known as the C-region). This region, along with the N-terminus of the mature protein, plays an important role in determining the cleavage sites.6
Long non-coding RNA DDX11-AS1 facilitates gastric cancer progression by regulating miR-873-5p/SPC18 axis
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2020
Zheng Ren, Xiaochun Liu, Yaoran Si, Desheng Yang
SPC18 protein, encoded by SEC11A, is one of the subunits of the signal peptidase complex and has catalytic activity of signal peptidase [33]. Several reports elucidated the association of SPC18 protein with tumorigenesis. For example, overexpression of SEC11A promoted cell growth and invasiveness in bladder cancer [34]. Down-regulation of SPC18 inhibited cell proliferation and invasive activity in colorectal cancer through inactivation of EGFR signalling [35]. Also, SPC18 expression was up-regulated in GC tissues, and SPC18 overexpression facilitated GC malignant progression via inducing TGF-a secretion [36].