title: The phocein homologue SmMOB3 is essential for vegetative cell fusion and sexual development in the filamentous ascomycete Sordaria macrospora.
abstract: Members of the striatin family and their highly conserved interacting protein phocein/Mob3 are key components in the regulation of cell differentiation in multicellular eukaryotes. The striatin homologue PRO11 of the filamentous ascomycete Sordaria macrospora has a crucial role in fruiting body development. Here, we functionally characterized the phocein/Mob3 orthologue SmMOB3 of S. macrospora. We isolated the gene and showed that both, pro11 and Smmob3 are expressed during early and late developmental stages. Deletion of Smmob3 resulted in a sexually sterile strain, similar to the previously characterized pro11 mutant. Fusion assays revealed that ∆Smmob3 was unable to undergo self-fusion and fusion with the pro11 strain. The essential function of the SmMOB3 N-terminus containing the conserved mob domain was demonstrated by complementation analysis of the sterile S. macrospora ∆Smmob3 strain. Downregulation of either pro11 in ∆Smmob3, or Smmob3 in pro11 mutants by means of RNA interference (RNAi) resulted in synthetic sexual defects, demonstrating for the first time the importance of a putative PRO11/SmMOB3 complex in fruiting body development.
authors.affiliation: Institute of Microbiology and Genetics, Department of Genetics of Eukaryotic Microorganisms, Georg-August University, Grisebachstr. 8, 37077, Göttingen, Germany.
authors.forename: Yasmine
authors.initials: Y
authors.lastname: Bernhards
authors.forename: Stefanie
authors.initials: S
authors.lastname: Pöggeler
mesh_terms: D000595:Amino Acid Sequence; D002459:Cell Fusion; D048690:Fruiting Bodies, Fungal / Q000166:cytology / Q000235:genetics* / Q000254:growth & development; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D034622:RNA Interference; D016415:Sequence Alignment; D020037:Sordariales / Q000737:chemistry / Q000166:cytology / Q000235:genetics* / Q000254:growth & development
chemical_list: D008565:Membrane Proteins; C430214:phocein