scholarly journals Secretory Nanoparticles of Neospora caninum Profilin-Fused with the Transmembrane Domain of GP64 from Silkworm Hemolymph

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 593 ◽  
Author(s):  
Suhaimi ◽  
Hiramatsu ◽  
Xu ◽  
Kato ◽  
Park
Keyword(s):  
Recombinant Proteins ◽  
Transmembrane Domain ◽  
Neospora Caninum ◽  
Signal Sequence ◽  
Toll Like Receptor ◽  
Bombyx Mori Nucleopolyhedrovirus ◽  
Silkworm Larvae ◽  
Silkworm Hemolymph ◽  
Agarose Beads ◽  
Bmnpv Bacmid

Neosporosis, which is caused by Neospora caninum, is a well-known disease in the veterinary field. Infections in pregnant cattle lead to abortion via transplacental (congenitally from mother to fetus) transmission. In this study, a N. caninum profilin (NcPROF), was expressed in silkworm larvae by recombinant Bombyx mori nucleopolyhedrovirus (BmNPV) bacmid and was purified from the hemolymph. Three NcPROF constructs were investigated, native NcPROF fused with an N-terminal PA tag (PA-NcPROF), PA-NcPROF fused with the signal sequence of bombyxin from B. mori (bx-PA-NcPROF), and bx-PA-NcPROF with additional C-terminal transmembrane and cytoplasmic domains of GP64 from BmNPV (bx-PA-NcPROF-GP64TM). All recombinant proteins were observed extra- and intracellularly in cultured Bm5 cells and silkworm larvae. The bx-PA-NcPROF-GP64TM was partly abnormally secreted, even though it has the transmembrane domain, and only it was pelleted by ultracentrifugation, but PA-NcPROF and bx-PA-NcPROF were not. Additionally, bx-PA-NcPROF-GP64TM was successfully purified from silkworm hemolymph by anti-PA agarose beads while PA-NcPROF and bx-PA-NcPROF were not. The purified bx-PA-NcPROF-GP64TM protein bound to its receptor, mouse Toll-like receptor 11 (TLR-11), and formed unique nanoparticles. These results suggest that profilin fused with GP64TM was secreted as a nanoparticle with binding affinity to its receptor and this nanoparticle formation is advantageous for the development of vaccines to N. caninum.

scholarly journals The PBN1 Gene of Saccharomyces cerevisiae: An Essential Gene That Is Required for the Post-translational Processing of the Protease B Precursor

Genetics ◽  
1998 ◽  
Vol 149 (3) ◽  
pp. 1277-1292 ◽  
Author(s):  
Rajesh R Naik ◽  
Elizabeth W Jones
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Secretory Pathway ◽  
Transmembrane Domain ◽  
Essential Gene ◽  
Signal Sequence ◽  
Signal Peptidase ◽  
Amino Terminal ◽  
Autocatalytic Cleavage ◽  
Protease B ◽  
Chromosome Iii

Abstract The vacuolar hydrolase protease B in Saccharomyces cerevisiae is synthesized as an inactive precursor (Prb1p). The precursor undergoes post-translational modifications while transiting the secretory pathway. In addition to N- and O -linked glycosylations, four proteolytic cleavages occur during the maturation of Prb1p. Removal of the signal peptide by signal peptidase and the autocatalytic cleavage of the large aminoterminal propeptide occur in the endoplasmic reticulum (ER). Two carboxy-terminal cleavages of the post regions occur in the vacuole: the first cleavage is catalyzed by protease A and the second results from autocatalysis. We have isolated a mutant, pbn1-1, that exhibits a defect in the ER processing of Prb1p. The autocatalytic cleavage of the propeptide from Prb1p does not occur and Prb1p is rapidly degraded in the cytosol. PBN1 was cloned and is identical to YCL052c on chromosome III. PBN1 is an essential gene that encodes a novel protein. Pbn1p is predicted to contain a sub-C-terminal transmembrane domain but no signal sequence. A functional HA epitope-tagged Pbn1p fusion localizes to the ER. Pbn1p is N-glycosylated in its amino-terminal domain, indicating a lumenal orientation despite the lack of a signal sequence. Based on these results, we propose that one of the functions of Pbn1p is to aid in the autocatalytic processing of Prb1p.

scholarly journals Monoclonal antibodies specific for low-affinity interleukin-3 (IL-3) binding protein AIC2A: evidence that AIC2A is a component of a high- affinity IL-3 receptor

Blood ◽  
1992 ◽  
Vol 79 (4) ◽  
pp. 895-903
Author(s):  
T Ogorochi ◽  
T Hara ◽  
HM Wang ◽  
K Maruyama ◽  
A Miyajima
Keyword(s):  
Monoclonal Antibodies ◽  
Transmembrane Domain ◽  
Signal Sequence ◽  
Amino Acid Level ◽  
Terminal Sequence ◽  
Chimeric Receptors ◽  
Interleukin 3 ◽  
High Affinity ◽  
Processing Site ◽  
Binding Component

Abstract Mouse interleukin-3 (IL-3) binds to its receptor with high and low affinities. Using anti-Aic2 antibody, two distinct cDNAs (AIC2A and AIC2B) were isolated. The AIC2A gene encodes a protein of 120 Kd that binds IL-3 with low affinity, whereas the AIC2B gene encodes a protein that is 91% identical to AIC2A at the amino acid level, but which does not bind IL-3. To study the structure of the functional high-affinity IL-3 receptor (IL-3R), we generated specific monoclonal antibodies against the AIC2A protein. We produced a soluble AIC2A protein by inserting a termination codon at the beginning of the transmembrane domain of the AIC2A cDNA. Soluble AIC2A protein expressed in COS7 cells was purified to homogeneity and three anti-AIC2A monoclonal antibody- producing hybridomas (3D1, 3D4, and 9D3) were obtained from a rat immunized with the purified soluble AIC2A protein. The antibodies were specific for the AIC2A protein and did not bind to the AIC2B protein. Using chimeric receptors between AIC2A and AIC2B, recognition sites of the antibodies were mapped. The antibodies immunoprecipitated a 120-Kd protein from IL-3-dependent PT18 cells. The N-terminal sequence of the 120-Kd protein was consistent with the predicted processing site of the signal sequence of the AIC2A protein. Staining of IL-3-dependent and IL- 3-independent cell lines with the 9D3 antibody were consistent with the IL-3 binding. The 9D3 antibody inhibited both the high-affinity IL-3 binding and the low-affinity binding, as well as IL-3-dependent proliferation. These results indicate that the AIC2A protein is a binding component of a high-affinity IL-3R.

High-level heterologous expression and secretion inStreptomyces lividansof two major antigenic proteins fromMycobacterium tuberculosis

2002 ◽  
Vol 48 (1) ◽  
pp. 43-48 ◽  
Author(s):  
Donald Tremblay ◽  
Johanne Lemay ◽  
Michel Gilbert ◽  
Yvan Chapdelaine ◽  
Claude Dupont ◽  
...  
Keyword(s):  
Amino Acids ◽  
Mycobacterium Tuberculosis ◽  
Recombinant Proteins ◽  
Signal Sequence ◽  
Culture Conditions ◽  
Extracellular Proteins ◽  
Protein Sequence Analysis ◽  
Downstream Box ◽  
High Yields ◽  
High Level

Two major antigens from Mycobacterium tuberculosis were produced by Streptomyces lividans as secreted extracellular proteins. An expression-secretion vector had been constructed that contained the promoter of xylanase A and the signal sequence of cellulase A. The latter contained two initiation codons preceded by a Shine-Dalgarno sequence plus eight nucleotides complementary to the 16S rRNA. The genes encoding the 38-kDa (Rv0934) and 19-kDa (Rv3763) proteins, respectively, were amplified by polymerase chain reaction and cloned into that vector. The recombinant proteins were then purified from the culture supernatants of the clones. The yields after purification were 80 mg/L for the 38-kDa protein and 200 mg/L for the 19-kDa protein. Sequence analysis of the N-terminal sequences showed a deletion of seven or eight amino acids for the 38-kDa protein, while in the 19-kDa protein 22 or 23 amino acids were lost, as compared with the respective wild-type proteins. However, the 19 kDa recombinant protein had the same N-terminal sequence as the one recovered from the M. tuberculosis culture supernatant. The high yields obtained for these two proteins demonstrated the potential of S. lividans as an alternative host for the production of recombinant proteins from M. tuberculosis. The culture conditions have yet to be worked out to minimize proteolytic degradation and to recover intact products.Key words: streptomycetes, downstream box, signal peptide, protein secretion, Mycobacterium tuberculosis.

scholarly journals Posttranslational Modifications Required for Cell Surface Localization and Function of the Fungal Adhesin Aga1p

2003 ◽  
Vol 2 (5) ◽  
pp. 1099-1114 ◽  
Author(s):  
Guohong Huang ◽  
Mingliang Zhang ◽  
Scott E. Erdman
Keyword(s):  
Cell Wall ◽  
Cell Surface ◽  
Posttranslational Modifications ◽  
Transmembrane Domain ◽  
Signal Sequence ◽  
Cell Types ◽  
Fungal Species ◽  
Surface Proteins ◽  
Functional Requirements

ABSTRACT Adherence of fungal cells to host substrates and each other affects their access to nutrients, sexual conjugation, and survival in hosts. Adhesins are cell surface proteins that mediate these different cell adhesion interactions. In this study, we examine the in vivo functional requirements for specific posttranslational modifications to these proteins, including glycophosphatidylinositol (GPI) anchor addition and O-linked glycosylation. The processing of some fungal GPI anchors, creating links to cell wall β-1,6 glucans, is postulated to facilitate postsecretory traffic of proteins to cell wall domains conducive to their functions. By studying the yeast sexual adhesin subunit Aga1p, we found that deletion of its signal sequence for GPI addition eliminated its activity, while deletions of different internal domains had various effects on function. Substitution of the Aga1p GPI signal domain with those of other GPI-anchored proteins, a single transmembrane domain, or a cysteine capable of forming a disulfide all produced functional adhesins. A portion of the cellular pool of Aga1p was determined to be cell wall resident. Aga1p and the α-agglutinin Agα1p were shown to be under glycosylated in cells lacking the protein mannosyltransferase genes PMT1 and PMT2, with phenotypes manifested only in MATα cells for single mutants but in both cell types when both genes are absent. We conclude that posttranslational modifications to Aga1p are necessary for its biogenesis and activity. Our studies also suggest that in addition to GPI-glucan linkages, other cell surface anchorage mechanisms, such as transmembrane domains or disulfides, may be employed by fungal species to localize adhesins.

scholarly journals Charged Residues in the Transmembrane Domains of Hepatitis C Virus Glycoproteins Play a Major Role in the Processing, Subcellular Localization, and Assembly of These Envelope Proteins

2000 ◽  
Vol 74 (8) ◽  
pp. 3623-3633 ◽  
Author(s):  
Laurence Cocquerel ◽  
Czeslaw Wychowski ◽  
Frederic Minner ◽  
François Penin ◽  
Jean Dubuisson
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Transmembrane Domain ◽  
Signal Sequence ◽  
Envelope Proteins ◽  
Viral Envelope ◽  
Hydrophobic Residues ◽  
The Family ◽  
Charged Residues ◽  
Membrane Spanning

ABSTRACT For most membrane proteins, the transmembrane domain (TMD) is more than just an anchor to the membrane. The TMDs of hepatitis C virus (HCV) envelope proteins E1 and E2 are extreme examples of the multifunctionality of such membrane-spanning sequences. Indeed, they possess a signal sequence function in their C-terminal half, play a major role in endoplasmic reticulum localization of E1 and E2, and are potentially involved in the assembly of these envelope proteins. These multiple functions are supposed to be essential for the formation of the viral envelope. As for the other viruses of the familyFlaviviridae, these anchor domains are composed of two stretches of hydrophobic residues separated by a short segment containing at least one fully conserved charged residue. Replacement of these charged residues by an alanine in HCV envelope proteins led to an alteration of all of the functions performed by their TMDs, indicating that these functions are tightly linked together. These data suggest that the charged residues of the TMDs of HCV glycoproteins play a key role in the formation of the viral envelope.

scholarly journals Membrane-anchored metalloprotease MDC9 has an α-secretase activity responsible for processing the amyloid precursor protein

1999 ◽  
Vol 343 (2) ◽  
pp. 371-375 ◽  
Author(s):  
Hisashi KOIKE ◽  
Shigeo TOMIOKA ◽  
Hiroyuki SORIMACHI ◽  
Takaomi C. SAIDO ◽  
Kei MARUYAMA ◽  
...  
Keyword(s):  
Amyloid Precursor Protein ◽  
Phorbol Ester ◽  
Transmembrane Domain ◽  
Signal Sequence ◽  
Sequence Similarity ◽  
Precursor Protein ◽  
Cos Cells ◽  
Secretase Activity ◽  
Epidermal Growth ◽  
Metalloprotease Inhibitor

MDC9, also known as meltrin γ, is a membrane-anchored metalloprotease. MDC9 contains several distinct protein domains: a signal sequence followed by a prodomain and a domain showing sequence similarity to snake venom metalloproteases, a disintegrin-like domain, a cysteine-rich region, an epidermal-growth-factor-like repeat, a transmembrane domain and a cytoplasmic domain. Here we demonstrate that MDC9 expressed in COS cells is cleaved between the prodomain and the metalloprotease domain. Further, when MDC9 was co-expressed in COS cells with amyloid precursor protein (APP695) and treated with phorbol ester, APP695 was digested exclusively at the α-secretory site in MDC9-expressing cells. When an artificial α-secretory site mutant was also co-expressed with MDC9 and treated with phorbol ester, APP secreted by α-secretase was not increased in conditional medium. Inhibition of MDC9 by a hydroxamate-based metalloprotease inhibitor, SI-27, enhanced β-secretase cleavage. These results suggest that MDC9 has an α-secretase-like activity and is activated by phorbol ester.

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