Disease relevance of STXBP1

• The recombinant p67 sequences were fused to the first 85 amino acid residues derived from a nonstructural gene (NS1) of influenza virus A [1].
• Given the caveat of the small number of cattle analyzed, insect cell-derived p67 does not appear to be superior to NS1-p67 as an immunogen, and the latter remains the molecule of choice for the development of vaccines against East Coast fever [2].
• Delivery of the p67 sporozoite antigen of Theileria parva by using recombinant Salmonella dublin: secretion of the product enhances specific antibody responses in cattle [3].
• The p67 sporozoite antigen of Theileria parva has been fused to the C-terminal secretion signal of Escherichia coli hemolysin and expressed in secreted form by attenuated Salmonella dublin aroA strain SL5631 [3].
• Boran calves were immunized with a his-GFP-p67 fusion protein (GFP:p67deltaSS) or with GP64:p67C, a protein fusion between a C-terminal domain of p67 and the baculovirus envelope protein GP64 [4].

High impact information on STXBP1

• In an attempt to develop an alternative immunization procedure, the gene encoding p67, a major surface antigen of sporozoites, has been expressed by using the plasmid expression vector pMG1 [1].
• Overexpression of an N-terminal fragment of p67(phox), a component of NADPH oxidase which interacts with Rac1, attenuated PDGF-induced cyclin D(1) promoter activity, whereas overexpression of the wild-type p67 did not [5].
• These results suggest that p67 contains terminal GlcNAc moieties O-linked to the protein [6].
• Glycosylation of eukaryotic peptide chain initiation factor 2 (eIF-2)-associated 67-kDa polypeptide (p67) and its possible role in the inhibition of eIF-2 kinase-catalyzed phosphorylation of the eIF-2 alpha-subunit [6].
• These results suggest that p67 activity in the cell may also be regulated post-transcriptionally by glycosylation of p67 protein [6].

Chemical compound and disease context of STXBP1

• The neutrophil NADPH oxidase activation factors, p47, p67 and the small guanosine-nucleotide-binding regulatory (G) protein Rac1, were expressed in a baculovirus/insect cell system and purified [7].
• Here, we report the expression of N- and C-terminal domains of p67 fused to the baculovirus envelope glycoprotein GP64 by cloning the appropriate p67 cDNA segments between the signal sequence and the major portion of GP64 [8].

Biological context of STXBP1

• We have reported previously that a 67-kDa polypeptide (p67) present in reticulocyte lysates protects the alpha-subunit of reticulocyte eukaryotic peptide chain initiation factor 2 (eIF-2) from phosphorylation by an eIF-2 kinase, heme-regulated protein synthesis inhibitor (Datta, B., Chakrabarti, D., Roy, A.L., and Gupta, N [6].
• OBJECTIVE: A 67 kDa Ca2+ binding protein (p67) from bovine hearts has recently been purified [9].
• This bacterially expressed antigen encoded all 709 amino acid residues of p67 fused to the C-terminal end of 87 residues derived from NS1, a structural protein of influenza virus, and a linker DNA sequence [2].
• Theileria annulata and Theileria parva both possess a major surface antigen on the sporozoite stage of the life-cycle, called SPAG-1 and p67, respectively [10].
• Species-specific synthetic oligonucleotide probes, restriction fragment length polymorphism (RFLP) analysis with cloned T. parva DNA probes, and DNA sequence analysis of the p67 sporozoite antigen gene confirmed that the waterbuck-passaged parasite was T. parva [11].

Anatomical context of STXBP1

• In this study, further biochemical and morphological experiments were carried out to examine whether the p67 is a member of the annexin family of proteins and how the protein is associated with the sarcolemma membrane [9].
• RESULTS: The p67 bound to acidic phospholipids and biological membranes in a Ca2+ dependent manner [9].
• Bovine leukocyte antigen major histocompatibility complex class II DRB3*2703 and DRB3*1501 alleles are associated with variation in levels of protection against Theileria parva challenge following immunization with the sporozoite p67 antigen [12].
• Immunogold electron microscopy was carried out to examine the subcellular localization of the p67 in muscle cells [13].
• Immunocytochemical localization of 67 KD Ca2+ binding protein (p67) in ventricular, skeletal, and smooth muscle cells [13].

Associations of STXBP1 with chemical compounds

• This radioactivity is resistant to endo-beta-N-acetylglucosamine F (+ peptide:N-glycosidase F) treatment but is completely lost when the 3H-labeled p67 is treated with sodium borohydride in mild alkali (beta-elimination reaction) [6].
• We now present evidence that this p67 contains multiple O-linked N-acetylglucosamine (GlcNAc) residues, and these glycosyl residues may be required for p67 activity to protect the eIF-2 alpha-subunit from eIF-2 kinase phosphorylation [6].
• By using serum antibodies from M. gallisepticum-infected chickens, we were able to demonstrate the immunogenic nature of PvpA and identify three additional highly immunogenic Triton X-114 phase proteins (p67, p72, and p75) also undergoing high-frequency phase variation spontaneously and independently [14].
• An oxidase activating complex from the cytosol of bovine neutrophils was purified by immunoaffinity using a monoclonal antibody specific for the 67 kDa cytosolic factor of oxidase activation (p67) and assayed for production of superoxide O2- in a cell-free system [15].

Analytical, diagnostic and therapeutic context of STXBP1

• Subunit vaccination using a recombinant sporozoite antigen (p67) has proved very promising, with levels of protection of the order of 70% being achieved [16].
• Immunoelectron microscopy showed that p67 seemed to be localised at the cytoplasmic side of the cardiac sarcolemma [9].
• Immunofluorescence microscopy revealed that the p67 was expressed in all these muscle cells, whereas anti-p36 antibody stained cells in connective tissues but failed to stain these muscle cells [13].

References