ABSTRACT
Human DOCK180, which was originally identified as a major protein bound to the Crk oncogene product, is an archetype of the CDM family of proteins, including Ced-5 of Caenorhabditis elegans and Mbc of Drosophila melanogaster. After DOCK180, at least three putative human proteins that manifest high amino acid sequence similarity to DOCK180 have been registered in the GenBank/EMBL database. We have designated one of them, KIAA0209, as DOCK2 and characterize here. DOCK2 mRNA was expressed mostly in peripheral blood cells, followed by slight expression in the spleen and thymus, whereas DOCK180 was expressed in all tissues tested except in peripheral blood cells. Immunostaining of human cadaver tissues revealed that the expression of DOCK2 was limited to the lymphocytes and macrophages of various organs. DOCK2 bound to and activated Rac1, as did DOCK180; however, DOCK2 did not bind to CrkII, which transduces signals at focal adhesions. Thus, DOCK180 and DOCK2 are regulators of Rac and function in adherent and non-adherent cells, respectively.
Subject(s)
Caenorhabditis elegans Proteins , Carrier Proteins/metabolism , Guanine Nucleotide Exchange Factors , Proteins/metabolism , Proto-Oncogene Proteins , Amino Acid Sequence , Carrier Proteins/chemistry , Carrier Proteins/isolation & purification , DNA, Complementary/chemistry , GTPase-Activating Proteins , Humans , Immunohistochemistry , Leukocytes/metabolism , Membrane Proteins/chemistry , Molecular Sequence Data , Protein Kinases/metabolism , Proteins/chemistry , Proto-Oncogene Proteins c-crk , RNA, Messenger/analysis , RNA, Messenger/metabolism , Sequence Homology, Amino Acid , Spleen/metabolism , Thymus Gland/metabolism , rac GTP-Binding Proteins/metabolism , rac1 GTP-Binding Protein/metabolism , RAC2 GTP-Binding ProteinABSTRACT
ER-35786 is a new parenteral 1 beta-methyl carbapenem with a broad antibacterial spectrum and a potent antipseudomonal activity. It showed high in vitro activity, comparable to those of meropenem and a new carbapenem, BO-2727, against methicillin-susceptible Staphylococcus aureus and streptococci, with MICs at which 90% of strains tested are inhibited (MIC90S) of < or = 0.39 microgram/ml. Against methicillin-resistant S. aureus, ER-35786 was the most active among the compounds tested, yet its MIC90 was 12.5 micrograms/ml. Against members of the family Enterobacteriaceae, Moraxella catarrhalis, and Haemophilus influenzae, ER-35786 inhibited 90% of strains tested at a concentration of < or = 1.56 micrograms/ml. The MIC90 of ER-35786 for Pseudomonas aeruginosa was 3.13 micrograms/ml, and the compound was more active than meropenem. In addition, the activity of ER-35786 against imipenem-, meropenem-, cefclidin-, or ceftazidime-resistant P. aeruginosa was equal to or higher than that of the most active reference compound. The in vivo activity of ER-35786 was consistent with this in vitro activity. The in vivo activity of ER-35786 was highest for systemic infection models with methicillin-resistant S. aureus and beta-lactam-resistant P. aeruginosa strains. In acute pneumonia caused by P. aeruginosa, ER-35786 produced a greater reduction in the viable cell count in the lungs than did imipenem-cilastatin or meropenem.
