Site-directed mutagenesis of CCR2 identified amino acid residues in transmembrane helices 1, 2, and 7 important for MCP-1 binding and biological functions.

Monocyte chemotactic protein-1 (MCP-1) binds its G-protein-coupled seven transmembrane (TM) receptor, CCR2B, and causes infiltration of monocytes/macrophages into areas of injury, infection or inflammation. To identify functionally important amino acid residues in CCR2B, we made specific mutations of nine residues selected on the basis of conservation in chemokine receptors and located TM1 (Tyr(49)), TM2 (Leu(95)), TM3 (Thr(117) and Tyr(120)), and TM7 (Ala(286), Thr(290), Glu(291), and His(297)) and in the extracellular loop 3 (Glu(278)). MCP-1 binding was drastically affected only by mutations in TM7.

Monocyte chemotactic protein-1 receptor CCR2B is a glycoprotein that has tyrosine sulfation in a conserved extracellular N-terminal region.

Monocyte chemotactic protein-1 (MCP-1) binding to its receptor, CCR2B, plays an important role in a variety of diseases involving infection, inflammation, and/or injury. In our effort to understand the molecular basis of this interaction and its biological consequences, we recognized a conserved hexad of amino acids at the N-terminal extracellular domain of several chemokine receptors, including CCR2B. Human embryonic kidney 293 cells expressing Flag-tagged CCR2B containing site-directed mutations in this region, 21-26, including a consensus tyrosine sulfation site were used to determine MCP-1 binding and its biological consequences.

[Expression of a partially modified delta-endotoxin gene from Bacillus thuringiensis var. tenebrionis in transgenic potato plants].

A modified gene (Bt77) of delta-endotoxin from Bacillus thuringiensis var. tenebrionis was constructed and cloned into pMON505. This binary transformation vector was introduced into Agrobacterium tumefaciens strains containing different helper disarmed Ti-plasmids, LBA4404, A281, and CBE21.