CSPP-L Associates with the Desmosome of Polarized Epithelial Cells and Is Required for Normal Spheroid Formation

Johan Sternemalm; Stefan Geimer; Kari-Anne M Frikstad; Kay O Schink; Trond Stokke; Sebastian Patzke

doi:10.1371/journal.pone.0134789

CSPP-L Associates with the Desmosome of Polarized Epithelial Cells and Is Required for Normal Spheroid Formation

PLoS One. 2015 Aug 4;10(8):e0134789. doi: 10.1371/journal.pone.0134789. eCollection 2015.

Authors

Johan Sternemalm¹, Stefan Geimer², Kari-Anne M Frikstad¹, Kay O Schink³, Trond Stokke¹, Sebastian Patzke¹

Affiliations

¹ Department of Radiation Biology, Division of Cancer Medicine, Surgery and Transplantation, Institute for Cancer Research, Oslo University Hospitals-Norwegian Radium Hospital, Oslo, Norway.
² Cell Biology/Electron Microscopy, University of Bayreuth, Bayreuth, Germany.
³ Department of Molecular Cell Biology, Division of Cancer Medicine, Surgery and Transplantation, Institute for Cancer Research, Oslo University Hospitals-Norwegian Radium Hospital, Oslo, Norway; Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Oslo, Norway.

Abstract

Deleterious mutations of the Centrosome/Spindle Pole associated Protein 1 gene, CSPP1, are causative for Joubert-syndrome and Joubert-related developmental disorders. These disorders are defined by a characteristic mal-development of the brain, but frequently involve renal and hepatic cyst formation. CSPP-L, the large protein isoform of CSPP1 localizes to microtubule ends of the mitotic mid-spindle and the ciliary axoneme, and is required for ciliogenesis. We here report the microtubule independent but Desmoplakin dependent localization of CSPP-L to Desmosomes in apical-basal polarized epithelial cells. Importantly, siRNA conferred depletion of CSPP-L or Desmoplakin promoted multi-lumen spheroid formation in 3D-cultures of non-ciliated human colon carcinoma Caco-2 cells. Multi-lumen spheroids of CSPP1 siRNA transfectants showed disrupted apical cell junction localization of the cytoskeleton organizing RhoGEF ECT2. Our results hence identify a novel, non-ciliary role for CSPP-L in epithelial morphogenesis.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adenocarcinoma / pathology
Animals
Cell Culture Techniques
Cell Cycle Proteins / antagonists & inhibitors
Cell Cycle Proteins / genetics
Cell Cycle Proteins / physiology*
Cell Line, Tumor
Cell Polarity
Colonic Neoplasms / pathology
Cytoskeleton / ultrastructure
Desmoplakins / physiology
Desmosomes / chemistry*
Dogs
Epithelial Cells / metabolism
Epithelial Cells / ultrastructure*
Humans
Intercellular Junctions / physiology
Intercellular Junctions / ultrastructure
Madin Darby Canine Kidney Cells
Mice
Microtubule-Associated Proteins / analysis
Microtubule-Associated Proteins / antagonists & inhibitors
Microtubule-Associated Proteins / genetics
Microtubule-Associated Proteins / physiology*
Microtubules / physiology
Morphogenesis
Neoplasm Proteins / antagonists & inhibitors
Neoplasm Proteins / genetics
Neoplasm Proteins / physiology
RNA Interference
RNA, Small Interfering / genetics
Spheroids, Cellular
Trachea / chemistry
Trachea / ultrastructure

Substances

CSPP1 protein, human
CSPP1 protein, mouse
Cell Cycle Proteins
DSP protein, human
Desmoplakins
Microtubule-Associated Proteins
Neoplasm Proteins
RNA, Small Interfering

Grants and funding

This project was financially supported through grants from the Regional Health Authorities of South-Eastern Norway (S.P.) and Norwegian Cancer Society (S.P., T.S.). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.