Proximity interactome mapping furthers a role for spinophilin in protein homeostasis

Emily T Claeboe; Keyana L Blake; Nikhil R Shah; Cameron W Morris; Basant Hens; Brady K Atwood; Sabrina Absalon; Amber L Mosley; Emma H Doud; Anthony J Baucum 2nd

doi:10.1016/j.isci.2025.113735

Proximity interactome mapping furthers a role for spinophilin in protein homeostasis

iScience. 2025 Oct 10;28(11):113735. doi: 10.1016/j.isci.2025.113735. eCollection 2025 Nov 21.

Authors

Emily T Claeboe¹, Keyana L Blake², Nikhil R Shah³, Cameron W Morris³, Basant Hens⁴, Brady K Atwood⁵, Sabrina Absalon¹, Amber L Mosley^{1

6

7

8}, Emma H Doud^{1

6}, Anthony J Baucum 2nd^{1

8}

Affiliations

¹ Department of Biochemistry, Molecular Biology, and Pharmacology, Indiana University School of Medicine, Indianapolis, IN, USA.
² Post-Baccalaureate Research Education Program, Indiana University Indianapolis, Indianapolis, IN, USA.
³ Medical Neuroscience Graduate Program, Indiana University School of Medicine, Indianapolis, IN, USA.
⁴ Pharmacology Graduate Training Program, Indiana University School of Medicine, Indianapolis, IN, USA.
⁵ Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN, USA.
⁶ Center for Proteome Analysis Indiana University School of Medicine, Indianapolis, IN, USA.
⁷ Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN, USA.
⁸ Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA.

Abstract

Spinophilin is a dendritic spine-enriched scaffolding and protein phosphatase 1-targeting protein. To detail spinophilin-interacting proteins, we created an UltraID and ALFA-tagged spinophilin-encoding construct that permits proximity labeling and orthogonal nanobody pull-down (ID-oPD) of spinophilin-associated protein complexes in heterologous cells. Using this ID-oPD approach, we identified 614 UltraID-specific and 312 UltraID-specific and spinophilin-selective spinophilin-interacting proteins in HEK293 cells and validated a subset of these using orthogonal approaches. Many of these proteins are involved in mRNA processing and translation. In the brain, we determined that spinophilin mRNA is highly neuropil localized and that spinophilin may normally function to limit its own expression but promote the expression of other postsynaptic density (PSD)-associated proteins. Overall, our use of an ID-oPD approach uncovers a putative role for spinophilin in mRNA translation and PSD protein expression.

Keywords: biochemistry applications; molecular interaction; properties of biomolecules; proteomics.

Associated data

figshare/10.6084/m9.figshare.29950442.v1

Abstract

Associated data

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