title: A fungal sarcolemmal membrane-associated protein (SLMAP) homolog plays a fundamental role in development and localizes to the nuclear envelope, endoplasmic reticulum, and mitochondria.
abstract: Sarcolemmal membrane-associated protein (SLMAP) is a tail-anchored protein involved in fundamental cellular processes, such as myoblast fusion, cell cycle progression, and chromosomal inheritance. Further, SLMAP misexpression is associated with endothelial dysfunctions in diabetes and cancer. SLMAP is part of the conserved striatin-interacting phosphatase and kinase (STRIPAK) complex required for specific signaling pathways in yeasts, filamentous fungi, insects, and mammals. In filamentous fungi, STRIPAK was initially discovered in Sordaria macrospora, a model system for fungal differentiation. Here, we functionally characterize the STRIPAK subunit PRO45, a homolog of human SLMAP. We show that PRO45 is required for sexual propagation and cell-to-cell fusion and that its forkhead-associated (FHA) domain is essential for these processes. Protein-protein interaction studies revealed that PRO45 binds to STRIPAK subunits PRO11 and SmMOB3, which are also required for sexual propagation. Superresolution structured-illumination microscopy (SIM) further established that PRO45 localizes to the nuclear envelope, endoplasmic reticulum, and mitochondria. SIM also showed that localization to the nuclear envelope requires STRIPAK subunits PRO11 and PRO22, whereas for mitochondria it does not. Taken together, our study provides important insights into fundamental roles of the fungal SLMAP homolog PRO45 and suggests STRIPAK-related and STRIPAK-unrelated functions.
authors.affiliation: Lehrstuhl für Allgemeine und Molekulare Botanik, Ruhr-Universität Bochum, Bochum, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Nordzieke
authors.affiliation: Institut für Neurobiologie, Westfälische Wilhelms-Universität Münster, Münster, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Zobel
authors.affiliation: Lehrstuhl für Analytische Chemie, Ruhr-Universität Bochum, Bochum, Germany.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Fränzel
authors.affiliation: Lehrstuhl für Analytische Chemie, Ruhr-Universität Bochum, Bochum, Germany.
authors.forename: Dirk A
authors.initials: DA
authors.lastname: Wolters
authors.affiliation: Lehrstuhl für Allgemeine und Molekulare Botanik, Ruhr-Universität Bochum, Bochum, Germany Ulrich.Kueck@rub.de Ines.Teichert@rub.de.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Kück
authors.affiliation: Lehrstuhl für Allgemeine und Molekulare Botanik, Ruhr-Universität Bochum, Bochum, Germany Ulrich.Kueck@rub.de Ines.Teichert@rub.de.
authors.forename: Ines
authors.identifier: http://orcid.org/0000-0002-2993-6756
authors.initials: I
authors.lastname: Teichert
mesh_terms: D000595:Amino Acid Sequence; D004721:Endoplasmic Reticulum / Q000502:physiology*; D005656:Fungal Proteins / Q000502:physiology; D025301:Hyphae / Q000166:cytology; D008565:Membrane Proteins / Q000502:physiology*; D008928:Mitochondria / Q000502:physiology*; D008954:Models, Biological; D008969:Molecular Sequence Data; D009685:Nuclear Envelope / Q000502:physiology*; D011485:Protein Binding; D015398:Signal Transduction; D020037:Sordariales / Q000166:cytology*
chemical_list: D005656:Fungal Proteins; D008565:Membrane Proteins