title: Schizophyllum commune A alpha mating-type proteins, Y and Z, form complexes in all combinations in vitro.
abstract: Tha A alpha locus of the basidiomycete fungus, Schizophyllum commune, regulates sexual development via proteins Y and Z. Each A alpha mating type encodes unique Y and Z isoforms. We used two isoforms of Y (Y4 and Y5) and two isoforms of Z (Z4 and Z5) in affinity assays of protein binding. These assays identified two types of protein interactions. Each full-length Y or Z protein binds to itself and other Y or Z proteins regardless of the A alpha mating type from which they are encoded (i.e., mating-type independent binding). A second type of binding, detected with partial-length polypeptides, occurs only between N-terminal regions of Y and Z proteins encoded from different A alpha mating types (e.g., Y4Z5 or Y5Z4); we refer to this binding as mating-type dependent binding. Deletion analysis shows that the Y4 specificity domain (an N-terminal region conferring recognition uniqueness to the Y4 isoform) is essential for mating-type dependent binding. Other regions of Y and Z are involved in mating-type independent binding. These results, obtained in vitro, raise the possibility that either of several protein complexes composed of Y and/or Z proteins may occur in vivo.
authors.affiliation: Department of Botany and Agricultural Biochemistry, University of Vermont, Burlington 05405-0086, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Asada
authors.forename: C
authors.initials: C
authors.lastname: Yue
authors.forename: J
authors.initials: J
authors.lastname: Wu
authors.forename: G P
authors.initials: GP
authors.lastname: Shen
authors.forename: C P
authors.initials: CP
authors.lastname: Novotny
authors.forename: R C
authors.initials: RC
authors.lastname: Ullrich
mesh_terms: D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D011485:Protein Binding; D011993:Recombinant Fusion Proteins; D012567:Schizophyllum / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D005656:Fungal Proteins; D018398:Homeodomain Proteins; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; C075905:homeodomain protein, Schizophyllum commune