The superoxide-producing NADPH oxidase consists of membrane-associated cytochrome b558 and cytosolic components, p47-phox and p67-phox. Recently, we have found a novel cytosolic component, p40-phox, which is tightly associated with p67-phox. In this study, we examined the translocation of p40-phox during activation of NADPH oxidase in a cell-free system using the membrane and the purified p47-p...

The ribonucleoprotein (RNP) p67 antigen was purified from rabbit thymus and used in an enzyme linked immunosorbent assay (ELISA) with low interassay variability to detect IgG antibodies to p67 in patients with autoimmune connective tissue diseases. These antibodies were found in eight (80%) patients with a clinical diagnosis of mixed connective tissue disease (MCTD) but also in 27 (40%) patient...

Differentiation of skeletal myogenic cells into multinucleated myotubes involves several cellular events including survival, migration, and motility. The level of eukaryotic initiation factor 2 (eIF2)-associated glycoprotein p67 gradually increases during the differentiation of C2C12 myoblasts into myotubes. It not only suppresses the rates of global protein synthesis, it inhibits the activatio...

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. The recombinant p67 antigen was detected in the supernatant of transformed bacterial cultures. Immunization trials in cattle revealed that SL5631 secreting the antigen provoked a 10-fold-h...

The level of p67 gradually increases when mouse C2C12 myoblasts differentiate into myotubes. During this differentiation, cycling myoblasts permanently withdraw from cell cycle. Largely, the cyclin/Cdk complexes drive eukaryotic cell cycle. To investigate whether p67 has any role(s) while C2C12 myoblasts are withdrawing from the cell cycle, we examined the levels of cyclins and Cdks in these my...

The assembly of cytosolic p47(phox) and p67(phox) with flavocytochrome b(558) at the membrane is crucial for activating the leukocyte NADPH oxidase that generates superoxide for microbial killing. p47(phox) and p67(phox) are linked via a high-affinity, tail-to-tail interaction involving a proline-rich region (PRR) and a C-terminal SH3 domain (SH3b), respectively, in their C-termini. This intera...

RNAi knockdown was employed to study the function of p67, a lysosome-associated membrane protein (LAMP)-like type I transmembrane lysosomal glycoprotein in African trypanosomes. Conditional induction of p67 dsRNA resulted in specific approximately 90% reductions in de novo p67 synthesis in both mammalian bloodstream and procyclic insect-stage parasites. Bloodstream cell growth was severely reta...

Immunity to Theileria parva infection in cattle is often parasite stock specific. The antigenic diversity which is expressed at the schizont stage of the parasite together with a wild reservoir of the organism in buffalo has complicated the development of effective disease control by immunization. We have previously shown that about 70% of cattle inoculated with recombinant forms of p67, a spor...

The eukaryotic initiation factor 2 (eIF-2)-associated 67-kDa polypeptide (p67) isolated from reticulocyte lysate protects the eIF-2 alpha subunit from eIF-2 kinase-catalyzed phosphorylation and promotes protein synthesis in the presence of active eIF-2 kinases. We have now studied the roles of p67 and eIF-2 kinases in regulation of protein synthesis using several animal cell lysates and an anim...

The phagocyte NADPH oxidase consists of multiple protein subunits that interact with each other to form a functional superoxide-generating complex. Although the essential components for superoxide production have been well characterized, other proteins potentially involved in the regulation of NADPH oxidase activation remain to be identified. We report here that the G i subunit of heterotrimeri...