Program Book - 27th Fungal Genetics Conference

FULL POSTER SESSION ABSTRACTSmetabolites and proteins, and all these carbon-starvation-associated products will affect markedly the microbiome in the ecological niche the autolyzingfungus occupies. A deeper understanding of the BrlA-mediated spatial and temporal regulatory mechanisms for conidiogenesis, cell death and autolysismay lead to the development of new industrial strains for heterologous protein production and/or novel biocontrol technologies.92. Whole-genome sequencing identifies novel alleles of genes required for organelle distribution and motility in Aspergillus nidulans. Kaeling Tan,Anthony Roberts, Martin Egan, Mark Chonofsky, Samara Reck-Peterson. Cell Biology, Harvard Med Sch, Boston, MA.Many organelles are transported long distances along microtubules in eukaryotic organisms by dynein and kinesin motors. To identify novel alleles andgenes required for microtubule-based transport, we performed a genetic screen in the filamentous fungus, Aspergillus nidulans. We fluorescently-labeledthree different organelle populations known to be cargo of dynein and kinesin in Aspergillus: nuclei, endosomes, and peroxisomes. We then used afluorescence microscopy-based screen to identify mutants with defects in the distribution or motility of these organelles. Using whole-genomesequencing, we found a number of single nucleotide polymorphisms (SNPs) that resulted in misdistribution of peroxisomes, endosomes, or nuclei. Some ofthese SNPs were novel alleles of cytoplasmic dynein/ nudA, Arp1/ nudK (dynactin), Lis1/ nudF, and kinesin-1/ kinA. Here, we characterize the in vivotransport defects in these novel mutants and analyze the single molecule in vitro motility properties of purified mutant motor proteins. We also describeour methods for using whole genome sequencing as a tool in mutagenesis studies in A. nidulans.93. Two methyltransferase protein complexes control fungal development and secondary metabolite production. Oezlem Sarikaya Bayram 1 , OezguerBayram 1 , Jong-Hwa Kim 2 , Keon-Sang Chae 3 , Dong-Min Han 4 , Kap-Hoon Han 2 , Gerhard Braus 1 . 1) Institute of Microbiology & Genetics, Dept. of MolecularMicrobiology and Genetics, Georg August University, Grisebachstr. 8, D 37077 Goettingen, Germany; 2) Department of Pharmaceutical Engineering,Woosuk University, Wanju, 565-701, Korea; 3) Division of Biological Sciences, Chonbuk National University, Jeonju, 561-756, Korea; 4) Division of LifeSciences, Wonkwang University, Iksan, 570-749, Korea.Coordination of development and secondary metabolism of the filamentous fungus Aspergillus nidulans requires the trimeric velvet complex consistingof VelB-VeA and the putative methyltransferase LaeA. We discovered a second trimeric protein complex for the same control mechanism consisting of anunusual zinc finger domain protein and even two subunits containing canonical methyltransferase domains. In contrast to velvet, which is assembled in thenucleus, the novel trimeric protein complex is formed at the plasma membrane. Functional green fluorescent protein fusions revealed that bothmethyltransferases are released from the membrane-bound zinc finger domain and migrate to the nucleus. The dimeric nuclear methyltransferasecomplex physically interacts with chromatin factors as heterochromatin protein and has an impact on the expression of asexual or sexual developmentalgenes as well as secondary metabolite gene clusters. Consistently, deletions of the corresponding genes result in defects in light response. Our resultssupport that a trimeric membrane complex initiates a signalling pathway which is mediated by two methyltransferases which transduce the signal tonuclear chromatin and affect gene expression. The interplay between the novel methyltransferase complex and the velvet complex remains to beelucidated.94. Control of Multicellular Development by the Physically Interacting Deneddylases DEN1/DenA and COP9 Signalosome. Josua Schinke 1 , MartinChristmann 1 , Tilo Schmaler 2 , Colin Gordon 3 , Xiaohua Huang 2 , Özgür Bayram 1 , Sina Stumpf 1 , Wolfgang Dubiel 2 , Gerhard Braus 1 . 1) Microbiology andGenetics, Georg-August-University, Göttingen, Niedersachsen, Germany; 2) Department of General, Visceral, Vascular and Thoracic Surgery, Division ofMolecular Biology, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany; 3) MRC Human Genetics Unit, Western General Hospital,Crewe Road, Edinburgh EH4 2XU, UK.Deneddylases remove the ubiquitin-like protein Nedd8 from modified proteins. An increased deneddylase activity has been associated to various humancancers. In contrast, we show here that a mutant strain of the model fungus Aspergillus nidulans which is deficient in two deneddylases is viable but canonly grow as a filament and has lost most of the potential for multicellular development. The DEN1/DenA and the COP9 signalosome (CSN) deneddylasesphysically interact in A. nidulans as well as in human cells, and CSN targets DEN1/DenA for protein degradation. Fungal development responds to light andrequires both deneddylases for an appropriate light reaction. In contrast to CSN which is necessary for sexual development, DEN1/DenA is required forasexual development. The CSN-DEN1/DenA interaction which affects DEN1/DenA protein levels presumably balances cellular deneddylase activity. Adeneddylase disequilibrium impairs multicellular development and suggests that control of deneddylase activity is important for multicellulardevelopment.95. Visualization of apical membrane domains in Aspergillus nidulans by Photoactivated Localization Microscopy (PALM). Norio Takeshita 1 , YujiIshitsuka 2 , Yiming Li 2 , Ulrich Nienhaus 2 , Reinhard Fischer 1 . 1) Dept. of Microbiology, Karlsruhe Institute of Technology, Karlsruhe, Germany; 2) Institute forApplied Physics, Karlsruhe Institute of Technology.Apical sterol-rich plasma membrane domains (SRDs), which can be viewed using the sterol-binding fluorescent dye filipin, are gaining attention for theirimportant roles in polarized growth of filamentous fungi. The size of SRDs is around a few mm, whereas the size of lipid rafts ranges in general between10-200 nm. In recent years, super-resolution microscope techniques have been improving and breaking the diffraction limit of conventional lightmicroscopy whose resolution limit is 250 nm. In this method, a lateral image resolution as high as 20 nm will be a powerful tool to investigate membranemicrodomains. To investigate deeply the relation of lipid membrane domains and protein localization, the distribution of microdomains in SRDs wereanalyzed by super-resolution microscope technique, Photoactivated Localization Microscopy (PALM). Membrane domains were visualized by each markerprotein tagged with photoconvertible fluorescent protein mEosFP for PALM. Size, number, distribution and dynamics of membrane domains, anddynamics of single molecules were investigated. Time-laps analysis revealed the dynamic behavior of exocytosis.144