Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:O76050 (neu)
 3,969 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A putative mitogen-activated protein kinase (MAPK) has recently been identified, which potentially phosphorylates the human epidermal growth factor (EGF) receptor at a physiological site (Thr-669) and is distinguished from other MAPKs/extracellular signal-regulated protein kinases (ERKs) on the basis of chromatographic, immunological, and kinetic data. Here we report that this newly discovered MAPK is physically associated with the EGF receptor in A431 cells and with the related receptor/tyrosine kinase HER2 (encoded by c-neu) in enzyme preparations obtained from Wilm's tumors. This human EGF receptor-associated kinase is characterized as a 40-kDa Thr-669 kinase that exists in a high molecular mass complex with the respective growth factor receptor. EGF treatment of A431 cells stimulates the tyrosine phosphorylation of p40 and increases Thr-669 kinase activity in p40-containing fractions. The 40-kDa kinase is recognized by affinity-purified polyclonal antibodies directed against the sea star p44mpk and a Pan-ERK antibody directed against the conserved subdomain VIII of MAPKs/ERKs, but is not recognized by antibodies selective for the rat p44erk1 and/or the p42mapk/erk2 isoforms, thus identifying the EGF receptor-associated kinase as a novel MAPK that may regulate receptor function in vivo.
 ...
PMID:Identification of a human epidermal growth factor receptor-associated protein kinase as a new member of the mitogen-activated protein kinase/extracellular signal-regulated protein kinase family. 768 42

An antibody-cytokine fusion protein, composed of the murine single-chain cytokine interleukin-12 (IL-12) genetically fused to a human IgG3 specific for the human tumor-associated antigen HER2/neu maintains antigen binding, cytokine bioactivity, and IL-12 heparin-binding activity. This latter property is responsible for the binding of the cytokine to glycosaminoglycans (GAGs) on the cell surface and the extracellular matrix and has been implicated in modulating IL-12 bioactivity. Previous studies indicate that the p40 subunit of human and murine IL-12 is responsible for the heparin-binding activity of this heterodimeric cytokine. In the present study we used bioinformatic analysis and site-directed mutagenesis to develop a version of the antibody-(IL-12) fusion protein without heparin-binding activity. This was accomplished by replacing the basic arginine (R) and lysine (K) residues in the cluster of amino acids 254-260 (RKKEKMK) of the murine IL-12 p40 subunit by the neutral non-polar amino acid alanine (A), generating an AAAEAMA mutant fusion protein. ELISA and flow cytometry demonstrated that the antibody fusion protein lacks heparin-binding activity but retains antigen binding. A T-cell proliferation assay showed IL-12 bioactivity in this construct. However, the IL-12 bioactivity is decreased compared to its non-mutated counterpart, which is consistent with an ancillary role of the heparin-binding site of IL-12 in modulating its activity. Thus, we have defined a cluster of amino acid residues with a crucial role in the heparin-binding activity of murine IL-12 in the context of an antibody-cytokine fusion protein.
 ...
PMID:Amino acid residues involved in the heparin-binding activity of murine IL-12 in the context of an antibody-cytokine fusion protein. 3112 97