BAR Proteins PSTPIP1/2 Regulate Podosome Dynamics and the Resorption Activity of Osteoclasts

Martin Sztacho; Sandra Segeletz; Maria Arantzazu Sanchez-Fernandez; Cornelia Czupalla; Christian Niehage; Bernard Hoflack

doi:10.1371/journal.pone.0164829

BAR Proteins PSTPIP1/2 Regulate Podosome Dynamics and the Resorption Activity of Osteoclasts

PLoS One. 2016 Oct 19;11(10):e0164829. doi: 10.1371/journal.pone.0164829. eCollection 2016.

Authors

Martin Sztacho¹, Sandra Segeletz¹, Maria Arantzazu Sanchez-Fernandez¹, Cornelia Czupalla¹, Christian Niehage¹, Bernard Hoflack¹

Affiliation

¹ Biotechnology Center, Technische Universität Dresden, Tatzberg 47-51, 01307, Dresden, Germany.

Abstract

Bone resorption in vertebrates relies on the ability of osteoclasts to assemble F-actin-rich podosomes that condense into podosomal belts, forming sealing zones. Sealing zones segregate bone-facing ruffled membranes from other membrane domains, and disassemble when osteoclasts migrate to new areas. How podosome/sealing zone dynamics is regulated remains unknown. We illustrate the essential role of the membrane scaffolding F-BAR-Proline-Serine-Threonine Phosphatase Interacting Proteins (PSTPIP) 1 and 2 in this process. Whereas PSTPIP2 regulates podosome assembly, PSTPIP1 regulates their disassembly. PSTPIP1 recruits, through its F-BAR domain, the protein tyrosine phosphatase non-receptor type 6 (PTPN6) that de-phosphophorylates the phosphatidylinositol 5-phosphatases SHIP1/2 bound to the SH3 domain of PSTPIP1. Depletion of any component of this complex prevents sealing zone disassembly and increases osteoclast activity. Thus, our results illustrate the importance of BAR domain proteins in podosome structure and dynamics, and identify a new PSTPIP1/PTPN6/SHIP1/2-dependent negative feedback mechanism that counterbalances Src and PI(3,4,5)P3 signalling to control osteoclast cell polarity and activity during bone resorption.

MeSH terms

Adaptor Proteins, Signal Transducing / chemistry
Adaptor Proteins, Signal Transducing / deficiency
Adaptor Proteins, Signal Transducing / genetics
Adaptor Proteins, Signal Transducing / metabolism*
Animals
Bone Resorption / metabolism*
Bone Resorption / pathology*
Cytoskeletal Proteins / chemistry
Cytoskeletal Proteins / deficiency
Cytoskeletal Proteins / genetics
Cytoskeletal Proteins / metabolism*
Gene Knockout Techniques
HEK293 Cells
Humans
Mice
Osteoclasts / metabolism*
Osteoclasts / pathology*
Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases / metabolism
Podosomes / metabolism*
Protein Domains
Protein Tyrosine Phosphatases, Non-Receptor / metabolism
Proteomics
RAW 264.7 Cells
RNA Interference

Substances

Adaptor Proteins, Signal Transducing
Cytoskeletal Proteins
Pstpip1 protein, mouse
Pstpip2 protein, mouse
Protein Tyrosine Phosphatases, Non-Receptor
Inpp5d protein, mouse
Inppl1 protein, mouse
Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases

Grants and funding

This work was supported in part by grants from Deutsche Forschungsgemeinschaft (TRR 13/2-08, TRR13/2-2013, HO 2584/2-1, HO 2584/1-1, HO 2584/6-1, HO 2584/8-1) and TU-Dresden (Support-the-best). SS was supported by the Marie Curie Initial Training Network (Euroclast, FP7-People- 2013-ITN: #607447). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.