Roles of NUDE and NUDF proteins of Aspergillus nidulans: insights from intracellular localization and overexpression effects.
The NUDF protein of the filamentous fungus Aspergillus nidulans functions in the cytoplasmic dynein pathway. It binds several proteins, including the NUDE protein. Green fluorescent protein-tagged NUDF and NUDA (dynein heavy chain) localize to linearly moving dashes ("comets") that coincide with microtubule ends. Herein, deletion of the nudE gene did not eliminate the comets of NUDF and NUDA, but affected the behavior of NUDA. Comets were also observed with the green fluorescent protein-tagged NUDE and its nonfunctional C-terminal domain. In addition, overexpressed NUDA and NUDE accumulated in specks that were either immobile or bounced randomly. Neither comets nor specks were observed with the functional N-terminal domain of NUDE, indicating that these structures are not essential for NUDE function. Furthermore, NUDF overproduction totally suppressed deletion of the nudE gene. This implies that the function of NUDE is secondary to that of NUDF. Unexpectedly, NUDF overproduction inhibited one conditional nudA mutant and all tested apsA mutants. An allele-specific interaction between the nudF and nudA genes is consistent with a direct interaction between NUDF and dynein heavy chain. Because APSA and its yeast homolog Num1p are cortical proteins, an interaction between the nudF and apsA genes suggests a role for NUDF at the cell cortex.
Efimov
Vladimir P
VP
Department of Pharmacology, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway 08854, USA. efimov@umdnj.edu
D001233:Aspergillus nidulans / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D004398:Dyneins / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D010641:Phenotype; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism
D005656:Fungal Proteins; D008164:Luminescent Proteins; C094692:NUDF protein, Emericella nidulans; D009687:Nuclear Proteins; C121041:RO-11 protein, Neurospora crassa; D011993:Recombinant Fusion Proteins; C092126:apsA protein, Aspergillus nidulans; D049452:Green Fluorescent Proteins; D004398:Dyneins; C096113:NUDA protein, Emericella nidulans