Two classes of homeodomain proteins specify the multiple a mating types of the mushroom Coprinus cinereus.
AUTOR(ES)
Kües, U
RESUMO
The A mating type locus of the mushroom Coprinus cinereus regulates essential steps in sexual development. The locus is complex and contains several functionally redundant, multiallelic genes that encode putative transcription factors. Here, we compare four genes from an A locus designated A42. Overall, the DNA sequences are very different (approximately 50% homology), but two classes of genes can be distinguished on the basis of a conserved homeodomain motif in their predicted proteins (HD1 and HD2). Development is postulated to be triggered by an HD1 and an HD2 gene from different A loci. Thus, proteins encoded by genes of the same locus must be distinguished from those encoded by another locus. Individual proteins of both classes recognize each other using the region N-terminal to the homeodomain. These N-terminal specificity regions (COP1 and COP2) are predicted to be helical and are potential dimerization interfaces. The amino acid composition of the C-terminal regions of HD1 proteins suggests a role in activation, and gene truncations indicate that this region is essential for function in vivo. A corresponding C-terminal region in HD2 proteins can be dispensed with in vivo. We will discuss these predicted structural features of the C. cinereus A proteins, their proposed interactions following a compatible cell fusion, and their similarities to the a1 and alpha 2 mating type proteins of the yeast Saccharomyces cerevisiae.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=160534Documentos Relacionados
- A chimeric homeodomain protein causes self-compatibility and constitutive sexual development in the mushroom Coprinus cinereus.
- An N-Terminal Dimerization Domain Permits Homeodomain Proteins To Choose Compatible Partners and Initiate Sexual Development in the Mushroom Coprinus cinereus.
- DNA-mediated transformation of the basidiomycete Coprinus cinereus.
- Inheritance of DNA methylation in Coprinus cinereus.
- Multiple Versions of the a Mating Type Locus of Coprinus Cinereus Are Generated by Three Paralogous Pairs of Multiallelic Homeobox Genes