The role of the B7 family molecules in the regulation of the immune response is well documented. A large body of experimental evidence indicates that costimulatory molecules such as B7-1, B7-2, B7-DC, B7-H1, B7-H2, B7-H3 and B7-H4 are critical for initiation, maintenance and down-regulation of the immune response. However the immunological function of butyrophilin (BTN)-like molecules, which are a part of the expanded B7 family, is not known.
View Article and Find Full Text PDFBackground: The recent H1N1 influenza pandemic illustrated the shortcomings of the vaccine manufacturing process. The A/California/07/2009 H1N1 pandemic influenza vaccine or A(H1N1)pdm09 was available late and in short supply as a result of delays in production caused by low yields and poor antigen stability. Recombinant technology offers the opportunity to shorten manufacturing time.
View Article and Find Full Text PDFThe multi-functional protein c-Cbl is an important modulator of actin cytoskeletal dynamics in diverse biological systems. We had previously reported that c-Cbl facilitates cell spreading and adhesion and suppresses anchorage-independent growth of v-Abl-transformed fibroblasts. To assess the importance of membrane localization of c-Cbl for the observed effects of c-Cbl in v-Abl-3T3 cells, we first mapped the membrane interactive domain(s) of c-Cbl.
View Article and Find Full Text PDFDownregulation of protein tyrosine kinases is a major function of the multidomain protein c-Cbl. This effect of c-Cbl is critical for both negative regulation of normal physiological stimuli and suppression of cellular transformation. In spite of the apparent importance of these effects of c-Cbl, their own regulation is poorly understood.
View Article and Find Full Text PDFBeyond regulating Rap activity, little is known regarding the regulation and function of the Rap GTPase-activating protein Rap1GAP. Tuberin and E6TP1 protein levels are tightly regulated through ubiquitin-mediated proteolysis. A role for these RapGAPs, along with SPA-1, as tumor suppressors has been demonstrated.
View Article and Find Full Text PDFFollowing discovery of c-Cbl, a cellular form of the transforming retroviral protein v-Cbl, multiple Cbl-related proteins have been identified in vertebrate and invertebrate organisms. c-Cbl and its homologues are capable of interacting with numerous proteins involved in cell signaling, including various molecular adapters and protein tyrosine kinases. It appears that Cbl proteins play several functional roles, acting both as multivalent adapters and inhibitors of various protein tyrosine kinases.
View Article and Find Full Text PDFThe protooncogenic protein c-Cbl has been shown to act as a multivalent adaptor and a negative regulator of protein tyrosine kinase-mediated signaling. Recent studies have implicated it in the regulation of cell adhesion-related events. We have previously shown that c-Cbl facilitates adhesion and spreading of v-Abl-transformed fibroblasts, and that these effects are dependent on its tyrosine phosphorylation.
View Article and Find Full Text PDFThe protooncogenic protein c-Cbl becomes tyrosine phosphorylated in normal cells in response to a variety of external stimuli, as well as in cells transformed by oncogenic protein tyrosine kinases. Tyrosine phosphorylation of c-Cbl upregulates its binding to multiple crucial signaling molecules. However, the biological consequences of c-Cbl-mediated signaling are insufficiently understood.
View Article and Find Full Text PDFHerpesvirus saimiri is a virus capable of inducing oncogenic transformation of T lymphocytes of New World primates and immortalizing human T cells in vitro. T lymphocytes immortalized by H. saimiri demonstrate functional biological responses to their antigens.
View Article and Find Full Text PDFProtooncogenic protein c-Cbl undergoes tyrosine phosphorylation in response to stimulation through the receptors for antigens, immunoglobulins, cytokines, and growth factors as well as through the integrins. Tyrosine phosphorylation of c-Cbl may play a functional role in signal transduction, since c-Cbl interacts with many crucial signaling molecules including protein-tyrosine kinases, adaptor proteins, and phosphatidylinositol 3'-kinase. Therefore, it is essential for our understanding of the functions of c-Cbl in signal transduction to identify its tyrosine phosphorylation sites, to determine the protein-tyrosine kinases that phosphorylate these sites, and to elucidate the role of these sites in the interactions of c-Cbl with other signaling proteins.
View Article and Find Full Text PDFFive clones were isolated from a human retina cDNA library whose cDNA inserts allowed reconstruction of the total sequence of the human clone cGMP phosphodiesterase alpha'-subunit cDNA comprising 3455 bp. The protein's deduced sequence contains 858 amino acids residues with molecular mass 99,169 Da. A substantial homology was revealed between the amino acid sequence of the human cones cGMP-phosphodiesterase alpha'-subunit and the corresponding sequences of alpha, beta, and alpha' subunits of visual cGMP-phosphodiesterase of bovine, murine, chicken and human retinas.
View Article and Find Full Text PDFFour independent phage clones containing the fragments of cone-specific cGMP phosphodiesterase (PDE) alpha' subunit (PDE-alpha') cDNA were isolated from the human cDNA library. The screening of the genomic library resulted in isolation of four independent phage clones with the fragments of human cone PDEalpha' gene including 5'-flanking region and exons ranged from 1 to 14 (overall 32 kilobases). Structural studies of the clones made it possible to establish the complete human cone PDEalpha' cDNA structure (3455 base pairs).
View Article and Find Full Text PDFcDNA clones encoding the beta-subunit of the photoreceptor cGMP phosphodiesterase (PDE) were isolated from a human retina library and their sequence was determined. The encoded polypeptide consists of 854 amino acid residues with a calculated molecular mass of 98,416 Da. Alignment of the deduced amino acid sequence with the earlier analysed alpha-, beta- and alpha'-subunits of bovine and mouse PDEs demonstrates a high homology.
View Article and Find Full Text PDFcDNA clones encoding the beta-subunit of the photoreceptor cGMP phosphodiesterase-(PDE) were isolated from a human retinal library. The encoded polypeptide has 854 amino acid residues with calculated molecular mass of 98416 Da. Alignment of the deduced amino acid sequence with the previously analysed alpha-, beta- and alpha'-subunits of the bovine and mouse PDEs demonstrates highly significant similarities.
View Article and Find Full Text PDFAn individual catalytic component of calmodulin-independent adenylate cyclase has been isolated from bovine brain cortex. Affinity chromatography on an immunosorbent was used. The amino acid sequence of adenylate cyclase as well as the corresponding nucleotide sequence of the cDNA has been determined.
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