Membrane-shaping proteins characterized by reticulon homology domains play an important part in the dynamic remodeling of the endoplasmic reticulum (ER). EMTHERA researchers and colleagues revealed that the membrane-shaping protein ARL6IP1 is involved in the selective degradation of the endoplasmic reticulum, and this process depends on ER-shaping protiens and their ubiquitination. Ubiquitination of proteins plays an important regulatory role in many cellular processes. Using innovative approaches, the EMTHERA team led by Ivan Đikić could show that ubiquitination stimulates autophagy of the endoplasmic reticulum (ER-phagy) by inducing receptor clustering in the ER membrane. Two manuscript describing the mechanistic details of this process and importance to prevent neurodegeneration were recently published:
González A, Covarrubias-Pinto A, Bhaskara RM, Glogger M, Kuncha SK, Xavier A, Seemann E, Misra M, Hoffmann ME, Bräuning B, Balakrishnan A, Qualmann B, Dötsch V, Schulman BA, Kessels MM, Hübner CA, Heilemann M, Hummer G, Đikić I. Ubiquitination regulates ER-phagy and remodelling of endoplasmic reticulum. Nature. 2023 Jun;618(7964):394-401. doi: 10.1038/s41586-023-06089-2.
Foronda H, Fu Y, Covarrubias-Pinto A, Bocker HT, González A, Seemann E, Franzka P, Bock A, Bhaskara RM, Liebmann L, Hoffmann ME, Katona I, Koch N, Weis J, Kurth I, Gleeson JG, Reggiori F, Hummer G, Kessels MM, Qualmann B, Mari M, Đikić I, Hübner CA. Heteromeric clusters of ubiquitinated ER-shaping proteins drive ER-phagy. Nature. 2023 Jun;618(7964):402-410. doi: 10.1038/s41586-023-06090-9.