title: The GYF domain protein CD2BP2 is critical for embryogenesis and podocyte function.
abstract: Scaffolding proteins play pivotal roles in the assembly of macromolecular machines such as the spliceosome. The adaptor protein CD2BP2, originally identified as a binding partner of the adhesion molecule CD2, is a pre-spliceosomal assembly factor that utilizes its glycine-tyrosine-phenylalanine (GYF) domain to co-localize with spliceosomal proteins. So far, its function in vertebrates is unknown. Using conditional gene targeting in mice, we show that CD2BP2 is crucial for embryogenesis, leading to growth retardation, defects in vascularization, and premature death at embryonic day 10.5 when absent. Ablation of the protein in bone marrow-derived macrophages indicates that CD2BP2 is involved in the alternative splicing of mRNA transcripts from diverse origins. At the molecular level, we identified the phosphatase PP1 to be recruited to the spliceosome via the N-terminus of CD2BP2. Given the strong expression of CD2BP2 in podocytes of the kidney, we use selective depletion of CD2BP2, in combination with next-generation sequencing, to monitor changes in exon usage of genes critical for podocyte functions, including VEGF and actin regulators. CD2BP2-depleted podocytes display foot process effacement, and cause proteinuria and ultimately lethal kidney failure in mice. Collectively, our study defines CD2BP2 as a non-redundant splicing factor essential for embryonic development and podocyte integrity.
authors.affiliation: Institute for Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany Leibniz-Institut fuer Molekulare Pharmakologie, 13125 Berlin, Germany.
authors.forename: Gesa I
authors.initials: GI
authors.lastname: Albert
authors.affiliation: Renal Division, University Hospital Freiburg, 79106 Freiburg, Germany Speman Graduate School for Medicine and Biology, University of Freiburg, 79106 Freiburg, Germany Faculty of Biology, University Freiburg, 79106 Freiburg, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Schell
authors.affiliation: Institute fuer Vegetative Physiologie, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany.
authors.forename: Karin M
authors.initials: KM
authors.lastname: Kirschner
authors.affiliation: Experimental Genetics and Cardiovascular Diseases, MDC, 13125 Berlin, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Schäfer
authors.affiliation: Transgenic Core Facility, Max-Planck-Institute of Molecular Cell Biology and Genetics, Dresden, Germany.
authors.forename: Ronald
authors.initials: R
authors.lastname: Naumann
authors.affiliation: Institute of Neuropathology, University of Freiburg, 79106 Freiburg, Germany.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Müller
authors.affiliation: Renal Division, University Hospital Freiburg, 79106 Freiburg, Germany Institute of Cell Biology & Anatomy, University of Freiburg, 79106 Freiburg, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Kretz
authors.affiliation: Leibniz-Institut fuer Molekulare Pharmakologie, 13125 Berlin, Germany.
authors.forename: Benno
authors.initials: B
authors.lastname: Kuropka
authors.affiliation: Institute for Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany.
authors.forename: Mathias
authors.initials: M
authors.lastname: Girbig
authors.affiliation: Experimental Genetics and Cardiovascular Diseases, MDC, 13125 Berlin, Germany.
authors.forename: Norbert
authors.initials: N
authors.lastname: Hübner
authors.affiliation: Leibniz-Institut fuer Molekulare Pharmakologie, 13125 Berlin, Germany.
authors.forename: Eberhard
authors.initials: E
authors.lastname: Krause
authors.affiliation: Institute fuer Vegetative Physiologie, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany christian.freund@fu-berlin.de klaus-peter.knobeloch@uniklinik-freiburg.de tobias.huber@uniklinik-freiburg.de holger.scholz@charite.de.
authors.forename: Holger
authors.initials: H
authors.lastname: Scholz
authors.affiliation: Renal Division, University Hospital Freiburg, 79106 Freiburg, Germany Speman Graduate School for Medicine and Biology, University of Freiburg, 79106 Freiburg, Germany BIOSS Centre for Biological Signaling Studies, Albert-Ludwigs-University, 79106 Freiburg, Germany christian.freund@fu-berlin.de klaus-peter.knobeloch@uniklinik-freiburg.de tobias.huber@uniklinik-freiburg.de holger.scholz@charite.de.
authors.forename: Tobias B
authors.initials: TB
authors.lastname: Huber
authors.affiliation: Institute of Neuropathology, University of Freiburg, 79106 Freiburg, Germany christian.freund@fu-berlin.de klaus-peter.knobeloch@uniklinik-freiburg.de tobias.huber@uniklinik-freiburg.de holger.scholz@charite.de.
authors.forename: Klaus-Peter
authors.initials: KP
authors.lastname: Knobeloch
authors.affiliation: Institute for Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany Leibniz-Institut fuer Molekulare Pharmakologie, 13125 Berlin, Germany christian.freund@fu-berlin.de klaus-peter.knobeloch@uniklinik-freiburg.de tobias.huber@uniklinik-freiburg.de holger.scholz@charite.de.
authors.forename: Christian
authors.initials: C
authors.lastname: Freund
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D017398:Alternative Splicing / Q000235:genetics; D000818:Animals; D047108:Embryonic Development / Q000235:genetics / Q000502:physiology; D005091:Exons / Q000235:genetics; D051379:Mice; D050199:Podocytes / Q000378:metabolism*; D012326:RNA Splicing / Q000235:genetics
chemical_list: D048868:Adaptor Proteins, Signal Transducing
keywords: CD2BP2; GYF domain; PP1; VEGF; alternative splicing; podocytes