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Dolnik A, Kanwal N, Mackert S, Halbedl S, Proepper C, Bockmann J, Schoen M, Boeckers TM, Kühl SJ, Schmeisser MJ. Sipa1l3/SPAR3 is targeted to postsynaptic specializations and interacts with the Fezzin ProSAPiP1/Lzts3. J Neurochem 2015; 136:28-35. [PMID: 26364583 DOI: 10.1111/jnc.13353] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 08/10/2015] [Accepted: 09/01/2015] [Indexed: 12/01/2022]
Abstract
Rap GTPase-activating proteins (RapGAPs) are essential for synaptic function as they tightly regulate synaptic Rap signaling. Among the most abundant synaptic RapGAPs in brain are the Spine-associated RapGAPs (SPARs) Sipa1l1/SPAR and Sipa1l2/SPAR2, whereas nothing has been reported on Sipa1l3/SPAR3. In this study, we show that Sipa1l3/SPAR3 is conserved across species, has a distinct expression pattern in the developing rat brain and is localized at excitatory postsynapses. We further demonstrate that the Sipa1l3/SPAR3 C-terminus is required for postsynaptic targeting and represents an interaction module for Fezzins such as ProSAPiP1/Lzts3, a binding partner of the postsynaptic scaffold protein Shank3. Taken together, our data imply that Sipa1l3/SPAR3 is a hitherto unknown synaptic RapGAP, which is targeted to postsynaptic specializations and interacts with Fezzins. Spine-associated RapGAPs (SPARs) are essential modulators of synaptic signaling. Our study is the first to characterize the SPAR family member Sipa1l3/SPAR3 in neuronal tissue. We show that Sipa1l3/SPAR3 is conserved across species, has a distinct expression pattern in brain and is localized to excitatory postsynapses via its C-terminus, which represents an interaction module for other postsynaptic proteins including the Fezzin ProSAPiP1/Lzts3.
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Affiliation(s)
- Anna Dolnik
- Institute for Anatomy and Cell Biology, Ulm University, Ulm, Germany
| | - Noreen Kanwal
- Institute for Anatomy and Cell Biology, Ulm University, Ulm, Germany.,International Graduate School in Molecular Medicine Ulm, IGradU, Ulm University, Ulm, Germany
| | - Sarah Mackert
- Institute for Anatomy and Cell Biology, Ulm University, Ulm, Germany.,International Graduate School in Molecular Medicine Ulm, IGradU, Ulm University, Ulm, Germany
| | - Sonja Halbedl
- Institute for Anatomy and Cell Biology, Ulm University, Ulm, Germany.,International Graduate School in Molecular Medicine Ulm, IGradU, Ulm University, Ulm, Germany
| | | | - Juergen Bockmann
- Institute for Anatomy and Cell Biology, Ulm University, Ulm, Germany
| | - Michael Schoen
- Institute for Anatomy and Cell Biology, Ulm University, Ulm, Germany
| | - Tobias M Boeckers
- Institute for Anatomy and Cell Biology, Ulm University, Ulm, Germany
| | - Susanne J Kühl
- Institute for Biochemistry and Molecular Biology, Ulm University, Ulm, Germany
| | - Michael J Schmeisser
- Institute for Anatomy and Cell Biology, Ulm University, Ulm, Germany.,Department of Neurology, Ulm University, Ulm, Germany
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