Deletion of Smgpi1 encoding a GPI‐anchored protein suppresses sterility of the STRIPAK mutant ΔSmmob3 in the filamentous ascomycete Sordaria macrospora. Issue 4 (26th May 2015)

• Record Type: Journal Article
• Authors: Frey, Stefan; Lahmann, Yasmine; Hartmann, Thomas; Seiler, Stephan; Pöggeler, Stefanie
• Is Part Of: Molecular microbiology. Volume 97:Issue 4(2015)
• Page Start: 676
• Page End: 697
• Publication Date: 2015-05-26
• Subjects: Molecular microbiology -- Periodicals; 572.829
• DOI: 10.1111/mmi.13054
• Languages: English
• ISSNs: 0950-382X

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p>The <underline>str</underline>iatin <underline>i</underline>nteracting <underline>p</underline>hosphatase <underline>a</underline>nd <underline>k</underline>inase (STRIPAK) complex, which is composed of striatin, protein phosphatase PP2A and kinases, is required for fruiting‐body development and cell fusion in the filamentous ascomycete <italic>S</italic><italic>ordaria macrospora</italic>. Here, we report on the interplay of the <underline>g</underline>lycosyl<underline>p</underline>hosphatidyl<underline>i</underline>nositol (GPI)‐anchored protein SmGPI1 with the kinase activator SmMOB3, a core component of human and fungal STRIPAK complexes. SmGPI1 is conserved among filamentous ascomycetes and was first identified in a yeast two‐hybrid screen using SmMOB3 as bait. The physical interaction of SmMOB3 and SmGPI1 was verified by co‐immunoprecipitation. <italic>In vivo</italic> localization and differential centrifugation revealed that SmGPI1 is predominantly secreted and attached to the cell wall but is also associated with mitochondria and appears to be a dual‐targeted protein. Deletion of <italic>S</italic><italic>mgpi1</italic> led to an increased number of fruiting bodies that were normally shaped but reduced in size. In addition, <italic>S</italic><italic>mmob3</italic> and <italic>S</italic><italic>mgpi1</italic> genetically interact. In the sterile ΔSmmob3 background deletion of <italic>S</italic><italic>mgpi1</italic> restores fertility, vegetative growth as well as hyphal‐fusion defects. The suppression effect was specific for the ΔSmmob3 mutant as deletion of <italic>S</italic><italic>mgpi1</italic> in other STRIPAK mutants does not restore fertility.</p> </abstract>