Ubiquitylation of the ER-Shaping Protein Lunapark via the CRL3KLHL12 Ubiquitin Ligase Complex
Laurensia Yuniati,
Angela Lauriola,
Manouk Gerritsen,
Susana Abreu,
Eric Ni,
Chiara Tesoriero,
Jacob O. Onireti,
Teck Yew Low,
Albert J.R. Heck,
Andrea Vettori,
Timothy Cardozo,
Daniele Guardavaccaro
Affiliations
Laurensia Yuniati
Hubrecht Institute-KNAW and University Medical Center Utrecht, 3584 CT Utrecht, the Netherlands
Angela Lauriola
Department of Biotechnology, University of Verona, 37134 Verona, Italy
Manouk Gerritsen
Hubrecht Institute-KNAW and University Medical Center Utrecht, 3584 CT Utrecht, the Netherlands
Susana Abreu
Hubrecht Institute-KNAW and University Medical Center Utrecht, 3584 CT Utrecht, the Netherlands
Eric Ni
Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, NYU Langone Health, New York, NY 10016, USA
Chiara Tesoriero
Department of Biotechnology, University of Verona, 37134 Verona, Italy
Jacob O. Onireti
Department of Biotechnology, University of Verona, 37134 Verona, Italy
Teck Yew Low
UKM Medical Molecular Biology Institute (UMBI), Universiti Kebangsaan Malaysia, 56000 Kuala Lumpur, Malaysia
Albert J.R. Heck
Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CH Utrecht, the Netherlands; The Netherlands Proteomics Center, 3584 CH Utrecht, the Netherlands
Andrea Vettori
Department of Biotechnology, University of Verona, 37134 Verona, Italy
Timothy Cardozo
Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, NYU Langone Health, New York, NY 10016, USA
Daniele Guardavaccaro
Hubrecht Institute-KNAW and University Medical Center Utrecht, 3584 CT Utrecht, the Netherlands; Department of Biotechnology, University of Verona, 37134 Verona, Italy; Corresponding author
Summary: Cullin-RING ligases (CRLs) control key cellular processes by promoting ubiquitylation of a multitude of soluble cytosolic and nuclear proteins. Subsets of CRL complexes are recruited and activated locally at cellular membranes; however, few CRL functions and substrates at these distinct cellular compartments are known. Here, we use a proteomic screen to identify proteins that are ubiquitylated at cellular membranes and found that Lunapark, an endoplasmic reticulum (ER)-shaping protein localized to ER three-way junctions, is ubiquitylated by the CRL3KLHL12 ubiquitin ligase. We demonstrate that Lunapark interacts with mechanistic target of rapamycin complex-1 (mTORC1), a central cellular regulator that coordinates growth and metabolism with environmental conditions. We show that mTORC1 binds Lunapark specifically at three-way junctions, and lysosomes, where mTORC1 is activated, make contact with three-way junctions where Lunapark resides. Inhibition of Lunapark ubiquitylation results in neurodevelopmental defects indicating that KLHL12-dependent ubiquitylation of Lunapark is required for normal growth and development.
