title: Identification of mitogen-activated protein kinase homologues from Leishmania mexicana.
abstract: Mitogen-activated protein kinases are key-regulatory elements in the differentiation, proliferation, apoptosis and stress response of eukaryotic cells. Our recent identification of a mitogen-activated protein kinase homologue in Leishmania mexicana which is essential for the proliferation of the amastigote stage of the parasite living in the parasitophorous vacuole of the infected macrophage prompted us to screen the genome of L. mexicana for additional mitogen-activated protein kinase homologues using degenerate oligonucleotide primers in a polymerase chain reaction amplification approach. We cloned and sequenced the genes for eight new mitogen-activated protein kinase homologues which were subsequently shown to be present in one copy per haploid genome. The mRNA levels of the kinases varied significantly in pro- and amastigote life stages of the parasite. We used the structural information of the p38 stress-activated protein kinase, which belongs to the family of mitogen-activated protein kinases, for the alignment of the deduced proteins and the verification of the predicted secondary structure elements. All new mitogen-activated protein kinases reveal the typical 12 subdomain primary structure, the conserved residues characterising serine/threonine protein kinases and the characteristic TXY motif in the phosphorylation lip. Typical features of some of the molecules are amino acid insertions between the subdomains and long carboxy-terminal amino acid extensions carrying putative src-homology 3-binding motifs.
authors.affiliation: Parasitology Section, Bernhard-Nocht-Institute for Tropical Medicine, Bernhard-Nocht-Strasse 74, D-20359 Hamburg, Germany. martin.wiese@bni-hamburg.de
authors.forename: Martin
authors.initials: M
authors.lastname: Wiese
authors.forename: Qiong
authors.initials: Q
authors.lastname: Wang
authors.forename: Iris
authors.initials: I
authors.lastname: Görcke
mesh_terms: D000818:Animals; D001483:Base Sequence; D018509:DNA, Helminth / Q000032:analysis*; D007894:Leishmania mexicana / Q000201:enzymology*; D008264:Macrophages / Q000469:parasitology; D051379:Mice; D008807:Mice, Inbred BALB C; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics*; D008969:Molecular Sequence Data; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D015398:Signal Transduction / Q000502:physiology
chemical_list: D018509:DNA, Helminth; D020928:Mitogen-Activated Protein Kinases