Sun, 20 Jul 2008 13:55:28 BST CiteULike: neils antibody http://www.citeulike.org/user/neils/tag/antibody CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/neils/article/2054444 <i>Biochem Biophys Res Commun, Vol. 300, No. 3. (Jan 2003), pp. 694-698.</i><br /><br />Activity of the STE20-related kinase hMINK was investigated. hMINK was expressed widely, though not ubiquitously, in human tissues; highest levels being found in haematopoietic tissues but also in brain, placenta, and lung. Mutagenesis revealed that T(191) and Y(193) in the substrate recognition loop of the catalytic domain were critical for kinase activity against exogenous substrates and autophosphorylation. A mutation on T(187) showed reduced enzymatic activity against exogenous substrates but retained autophosphorylation activity. Phosphorylation was confirmed by the use of a phospho-specific T(187) antibody. hMINK activated the JNK signal transduction pathway and optimal JNK activation occurred when the C-terminus was deleted. In addition, overexpression of the C-terminal domain devoid of kinase activity also resulted in significant activation of the JNK pathway. These data suggest that hMINK requires an activation step that dissociates the C terminal, thereby freeing the catalytic domain to interact with substrates. Models for receptor-mediated activation of hMINK are discussed. Identification of residues which regulate activity of the STE20-related kinase hMINK. Jaeseung Lim Andrew Lennard Paul Sheppard Stuart Kellie Biochem Biophys Res Commun, Vol. 300, No. 3. (Jan 2003), pp. 694-698. 2007-12-04T03:22:10-00:00 2003 Biochem Biophys Res Commun 300 3 694 698 amino-acid antibody article-predikin cell cerevisiae channel cloning data human jnk kidney kinase line mitogen-activated molecular mutagenesis organ phosphorylation potassium protein protein-serine-threonine relationship saccharomyces sequence site-directed specificity structure structure-activity tertiary voltage-gated http://www.citeulike.org/user/neils/article/2054431 <i>J Biol Chem, Vol. 279, No. 24. (Jun 2004), pp. 24957-24964.</i><br /><br />The C-terminal repeat domain (CTD) of the largest subunit of RNA polymerase II is composed of tandem heptad repeats with consensus sequence Tyr1-Ser2-Pro3-Thr4-Ser5-Pro6-Ser7. In yeast, this heptad sequence is repeated about 26 times, and it becomes hyperphosphorylated during transcription predominantly at serines 2 and 5. A network of kinases and phosphatases combine to determine the CTD phosphorylation pattern. We sought to determine the positional specificity of phosphorylation by yeast CTD kinase-I (CTDK-I), an enzyme implicated in various nuclear processes including elongation and pre-mRNA 3'-end formation. Toward this end, we characterized monoclonal antibodies commonly employed to study CTD phosphorylation patterns and found that the H5 monoclonal antibody reacts with CTD species phosphorylated at Ser2 and/or Ser5. We therefore used antibody-independent methods to study CTDK-I, and we found that CTDK-I phosphorylates Ser5 of the CTD if the CTD substrate is either unphosphorylated or prephosphorylated at Ser2. When Ser5 is already phosphorylated, CTDK-I phosphorylates Ser2 of the CTD. We also observed that CTDK-I efficiently generates doubly phosphorylated CTD repeats; CTD substrates that already contain Ser2-PO(4) or Ser5-PO(4) are more readily phosphorylated CTDK-I than unphosphorylby ated CTD substrates. C-terminal repeat domain kinase I phosphorylates Ser2 and Ser5 of RNA polymerase II C-terminal domain repeats. Janice Jones Hemali Phatnani Timothy Haystead Justin Macdonald Munir Alam Arno Greenleaf J Biol Chem, Vol. 279, No. 24. (Jun 2004), pp. 24957-24964. 2007-12-04T03:22:10-00:00 2004 J Biol Chem 279 24 24957 24964 amino-acid antibody article-predikin data kinase molecular monoclonal phosphorylation polymerase protein repetitive rna saccharomycetales sequence serine specificity substrate