title: The important role of actinin-like protein (AcnA) in cytokinesis and apical dominance of hyphal cells in Aspergillus nidulans.
abstract: The actin cytoskeleton is involved in many processes in eukaryotic cells, including interaction with a wide variety of actin-binding proteins such as the actin-capping proteins, the actin filament nucleators and the actin cross-linking proteins. Here, we report the identification and characterization of an actinin-like protein (AcnA) from the filamentous fungus Aspergillus nidulans. Not only did the depletion of AcnA by alcA(p) promoter repression or the deletion of AcnA result in explicit abnormalities in septation and conidiation, but also the acnA mutants induced a loss of apical dominance in cells with dichotomous branching, in which a new branch was formed by splitting the existing tip in two. Consequently, the colony showed flabellate edges. Moreover, we found that the localization of the GFP-AcnA fusion was quite dynamic. In the isotropic expansion phase of the germinated spore, GFP-AcnA was organized as cortical patches with cables lining the cell wall. Subsequently, GFP-AcnA was localized to the actively growing hyphal tips and to the sites of septation in the form of combined double contractile rings. Our data suggest that AcnA plays an important role in cytokinesis and apical dominance of hyphal cells, possibly via actin-dependent polarization maintenance and medial ring establishment in A. nidulans. This is the first report, to our knowledge, of the function of an actinin-like protein in filamentous fungi.
authors.affiliation: Nanjing Engineering and Technology Research Center for Microbiology, Jiangsu Key Laboratory for Bioresource Technology, College of Life Sciences, Nanjing Normal University, Nanjing 210046, PR China.
authors.forename: Jinjun
authors.initials: J
authors.lastname: Wang
authors.affiliation: Nanjing Engineering and Technology Research Center for Microbiology, Jiangsu Key Laboratory for Bioresource Technology, College of Life Sciences, Nanjing Normal University, Nanjing 210046, PR China.
authors.forename: Hongqin
authors.initials: H
authors.lastname: Hu
authors.affiliation: Nanjing Engineering and Technology Research Center for Microbiology, Jiangsu Key Laboratory for Bioresource Technology, College of Life Sciences, Nanjing Normal University, Nanjing 210046, PR China.
authors.forename: Sha
authors.initials: S
authors.lastname: Wang
authors.affiliation: Nanjing Engineering and Technology Research Center for Microbiology, Jiangsu Key Laboratory for Bioresource Technology, College of Life Sciences, Nanjing Normal University, Nanjing 210046, PR China.
authors.forename: Jie
authors.initials: J
authors.lastname: Shi
authors.affiliation: Nanjing Engineering and Technology Research Center for Microbiology, Jiangsu Key Laboratory for Bioresource Technology, College of Life Sciences, Nanjing Normal University, Nanjing 210046, PR China.
authors.forename: Shaochun
authors.initials: S
authors.lastname: Chen
authors.affiliation: Nanjing Engineering and Technology Research Center for Microbiology, Jiangsu Key Laboratory for Bioresource Technology, College of Life Sciences, Nanjing Normal University, Nanjing 210046, PR China.
authors.forename: Hua
authors.initials: H
authors.lastname: Wei
authors.affiliation: Nanjing Engineering and Technology Research Center for Microbiology, Jiangsu Key Laboratory for Bioresource Technology, College of Life Sciences, Nanjing Normal University, Nanjing 210046, PR China.
authors.forename: Xushi
authors.initials: X
authors.lastname: Xu
authors.affiliation: Nanjing Engineering and Technology Research Center for Microbiology, Jiangsu Key Laboratory for Bioresource Technology, College of Life Sciences, Nanjing Normal University, Nanjing 210046, PR China.
authors.forename: Ling
authors.initials: L
authors.lastname: Lu
mesh_terms: D000185:Actinin / Q000235:genetics / Q000378:metabolism*; D001233:Aspergillus nidulans / Q000166:cytology / Q000502:physiology*; D016764:Cell Polarity; D003001:Cloning, Molecular; D048749:Cytokinesis; D004271:DNA, Fungal / Q000235:genetics; D049452:Green Fluorescent Proteins; D025301:Hyphae / Q000166:cytology / Q000502:physiology*; D010802:Phylogeny; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D017386:Sequence Homology, Amino Acid; D013172:Spores, Fungal / Q000378:metabolism
chemical_list: D004271:DNA, Fungal; D011993:Recombinant Fusion Proteins; D000185:Actinin; D049452:Green Fluorescent Proteins