Evidence for coordinated induction and repression of ecto-5'-nucleotidase (CD73) and the A2a adenosine receptor in a human B cell line.

In the human B cell line P493-6 two mitogenic signals, the Epstein-Barr virus nuclear antigen 2 (EBNA2) and myc, can be independently regulated by means of an estrogen receptor fusion construct or an inducible expression vector, respectively. Shut off of EBNA2, either in the presence or absence of myc, leads to a significant increase in enzymatic activity and surface expression of ecto-5'-nucleotidase (CD73) as well as an increased adenosine receptor response in cyclic AMP formation. Shut off of myc expression has a small additional positive effect on CD73 activity.

Genomic organization and molecular characterization of a gene encoding HsPXF, a human peroxisomal farnesylated protein.

A protein modification essential for the cellular sorting of many biologically relevant proteins is the covalent attachment of prenyl lipids by specific transferases. Isoprenylation is known to render protein domains hydrophobic, thereby facilitating the interaction with lipid bilayers and/or membrane proteins. The target for the modification with farnesyl groups is the COOH-terminal sequence CaaX.

Ecto-5'-nucleotidase activity is not required for T cell activation through CD73.

It had previously been shown that CD73 (ecto-5'-nucleotidase) expressed on 30% of normal human peripheral T-lymphocytes can mediate costimulatory signals in T cell activation. To check for a possible contribution of the catalytic property of CD73 to this function transfected cell lines were created. Using site-directed mutagenesis on human CD73 cDNA the codons of His92 and His194 were exchanged for alanine codons.

The antibody MY4 recognizes CD14 on porcine monocytes and macrophages.

Several monoclonal antibodies directed against the human CD14 antigen have been established. We now report that the antibody My4, but not LeuM3, reacts with porcine monocytes. Among porcine peripheral blood mononuclear cells (PBMC), 14.