title: Two proteins with different functions are derived from the KlHEM13 gene.
abstract: Two proteins that differ at the N terminus (l-KlCpo and s-KlCpo) are derived from KlHEM13, a single-copy-number gene in the haploid genome of Kluyveromyces lactis. Two transcriptional start site (tss) pools are detectable using primer extension, and their selection is heme dependent. One of these tss pools is located 5' of the first translation initiation codon (TIC) in the open reading frame of KlHEM13, while the other is located between the first and second TICs. In terms of functional significance, only s-KlCpo complements the heme deficiency caused by the Δhem13 deletion in K. lactis. Data obtained from immune detection in subcellular fractions, directed mutagenesis, chromatin immunoprecipitation (ChIP) assays, and the functional relevance of ΔKlhem13 deletion for KlHEM13 promoter activity suggest that l-KlCpo regulates KlHEM13 transcription. A hypothetical model of the evolutionary origins and coexistence of these two proteins in K. lactis is discussed.
authors.affiliation: Dpto. de Biología Celular y Molecular, F. Ciencias, Universidad de A Coruña, Campus de A Zapateira s/n, A Coruña 15071, Spain.
authors.forename: Angel
authors.initials: A
authors.lastname: Vizoso Vázquez
authors.forename: Moisés
authors.initials: M
authors.lastname: Blanco
authors.forename: Justyna
authors.initials: J
authors.lastname: Zaborowska
authors.forename: Pilar
authors.initials: P
authors.lastname: Soengas
authors.forename: M Isabel
authors.initials: MI
authors.lastname: González-Siso
authors.forename: Manuel
authors.initials: M
authors.lastname: Becerra
authors.forename: Esther
authors.initials: E
authors.lastname: Rodríguez-Belmonte
authors.forename: M Esperanza
authors.initials: ME
authors.lastname: Cerdán
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003304:Coproporphyrinogen Oxidase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D007716:Kluyveromyces / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D011401:Promoter Regions, Genetic; D017434:Protein Structure, Tertiary; D024363:Transcription Initiation Site; D014158:Transcription, Genetic
chemical_list: D005656:Fungal Proteins; D003304:Coproporphyrinogen Oxidase