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mTORC1 controls Golgi architecture and vesicle secretion by phosphorylation of SCYL1. Nat Commun 2022; 13:4685. [PMID: 35948564 PMCID: PMC9365812 DOI: 10.1038/s41467-022-32487-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 07/30/2022] [Indexed: 12/04/2022] Open
Abstract
The protein kinase mechanistic target of rapamycin complex 1 (mTORC1) is a master regulator of cell growth and proliferation, supporting anabolic reactions and inhibiting catabolic pathways like autophagy. Its hyperactivation is a frequent event in cancer promoting tumor cell proliferation. Several intracellular membrane-associated mTORC1 pools have been identified, linking its function to distinct subcellular localizations. Here, we characterize the N-terminal kinase-like protein SCYL1 as a Golgi-localized target through which mTORC1 controls organelle distribution and extracellular vesicle secretion in breast cancer cells. Under growth conditions, SCYL1 is phosphorylated by mTORC1 on Ser754, supporting Golgi localization. Upon mTORC1 inhibition, Ser754 dephosphorylation leads to SCYL1 displacement to endosomes. Peripheral, dephosphorylated SCYL1 causes Golgi enlargement, redistribution of early and late endosomes and increased extracellular vesicle release. Thus, the mTORC1-controlled phosphorylation status of SCYL1 is an important determinant regulating subcellular distribution and function of endolysosomal compartments. It may also explain the pathophysiology underlying human genetic diseases such as CALFAN syndrome, which is caused by loss-of-function of SCYL1. mTORC1 is a master regulator of cell growth with well-known functions in inhibiting autophagic vesicle formation. Here, the authors show that mTORC1 also affects Golgi architecture and vesicle secretion by phosphorylating the scaffold protein SCYL1.
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Alotaibi M, Aldhubaiban D, Alasmari A, Alotaibi L. A Case of Geroderma Osteodysplasticum Syndrome: Unique Clinical Findings. Glob Med Genet 2021; 9:175-178. [PMID: 35707774 PMCID: PMC9192187 DOI: 10.1055/s-0041-1740468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 10/22/2021] [Indexed: 11/10/2022] Open
Abstract
Geroderma osteodysplasticum (GO; MIM 231070) is characterized by a typical progeroid facial appearance, wrinkled, lax skin, joint laxity, skeletal abnormalities with variable degree of osteopenia, frequent fractures, scoliosis, bowed long bones, vertebral collapse, and hyperextensible fingers. The disorder results from mutations in the GORAB—golgin, RAB6 interacting. This gene encodes a member of the golgin family, a group of coiled-coil proteins on golgin that maps to chromosome 1q24. The encoded protein has a function in the secretory pathway, was identified by terminal kinase-like protein, and thus, it may function in mitosis. Mutations in this gene have been associated with GO. Herein, we describe the clinical presentation of one young male patient from related Saudi parents. Mutations, a homozygous frameshift mutation (c.306dup p.(pro 103 Thrfs*20)). Interestingly, phenotypic variability was observed in this patient with GO features that were more atypical than the cases reported in the literature as he looks tall stature where most of the cases reported were short and arachnodactyly fingers which mimic other syndromes.
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Affiliation(s)
- Maha Alotaibi
- Department of Genetics, Children's Hospital, King Saud Medical City, Riyadh, Saudi Arabia
| | - Deema Aldhubaiban
- Department of Periodontology, King Saud Medical City, Riyadh, Saudi Arabia
| | - Ahmed Alasmari
- Department of Orthodontics, King Saud Medical City, Riyadh, Saudi Arabia
| | - Leena Alotaibi
- Collage of Medicine, King Saud bin Abdul-Aziz University for Health Sciences, Riyadh, Saudi Arabia
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Narrowing down the region responsible for 1q23.3q24.1 microdeletion by identifying the smallest deletion. Hum Genome Var 2019; 6:47. [PMID: 31645985 PMCID: PMC6804575 DOI: 10.1038/s41439-019-0079-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Revised: 09/16/2019] [Accepted: 09/16/2019] [Indexed: 11/24/2022] Open
Abstract
Interstitial deletions of 1q23.3q24.1 are rare. Here, chromosomal microarray testing identified a de novo microdeletion of arr[GRCh37]1q23.3q24.1(164816055_165696996) × 1 in a patient with moderate developmental delay, hearing loss, cryptorchidism, and other distinctive features. The clinical features were common to those previously reported in patients with overlapping deletions. The patient’s deletion size was 881 kb—the smallest yet reported. This therefore narrowed down the deletion responsible for the common clinical features. The deleted region included seven genes; deletion of LMX1A, RXRG, and ALDH9A1 may have caused our patient’s neurodevelopmental delay.
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Yang H, Albiol L, Chan WL, Wulsten D, Seliger A, Thelen M, Thiele T, Spevak L, Boskey A, Kornak U, Checa S, Willie BM. Examining tissue composition, whole-bone morphology and mechanical behavior of Gorab Prx1 mice tibiae: A mouse model of premature aging. J Biomech 2017; 65:145-153. [PMID: 29108851 DOI: 10.1016/j.jbiomech.2017.10.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 10/05/2017] [Accepted: 10/15/2017] [Indexed: 11/30/2022]
Abstract
Gerodermia osteodysplastica (GO) is a segmental progeroid disorder caused by loss-of-function mutations in the GORAB gene, associated with early onset osteoporosis and bone fragility. A conditional mouse model of GO (GorabPrx1) was generated in which the Gorab gene was deleted in long bones. We examined the biomechanical/functional relevance of the GorabPrx1 mutants as a premature aging model by characterizing bone composition, tissue-level strains, and whole-bone morphology and mechanical properties of the tibia. MicroCT imaging showed that GorabPrx1 tibiae had an increased anterior convex curvature and decreased cortical cross-sectional area, cortical thickness and moments of inertia, compared to littermate control (LC) tibiae. Fourier transform infrared (FTIR) imaging indicated a 34% decrease in mineral/matrix ratio and a 27% increase in acid phosphate content in the posterior metaphyseal cortex of the GorabPrx1 tibiae (p < .05), suggesting delayed mineralization. In vivo strain gauge measurement and finite element analysis showed ∼two times higher tissue-level strains within the GorabPrx1 tibiae relative to LC tibiae when subjected to axial compressive loads of the same magnitude. Three-point bending tests suggested that GorabPrx1 tibiae were weaker and more brittle, as indicated by decreasing whole-bone strength (46%), stiffness (55%), work-to-fracture (61%) and post-yield displacement (47%). Many of these morphological and biomechanical characteristics of the GorabPrx1 tibia recapitulated changes in other animal models of skeletal aging. Future studies are necessary to confirm how our observations might guide the way to a better understanding and treatment of GO.
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Affiliation(s)
- Haisheng Yang
- Department of Biomedical Engineering, College of Life Science and Bioengineering, Beijing University of Technology, Beijing, China; Research Centre, Shriners Hospital for Children-Canada, Department of Pediatric Surgery, McGill University, Montreal, Canada
| | - Laia Albiol
- Julius Wolff Institute, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Wing-Lee Chan
- Institute for Medical Genetics and Human Genetics, Charité-Universitätsmedizin Berlin, Germany
| | - Dag Wulsten
- Julius Wolff Institute, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Anne Seliger
- Julius Wolff Institute, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Michael Thelen
- Institute for Medical Genetics and Human Genetics, Charité-Universitätsmedizin Berlin, Germany
| | - Tobias Thiele
- Julius Wolff Institute, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | | | | | - Uwe Kornak
- Institute for Medical Genetics and Human Genetics, Charité-Universitätsmedizin Berlin, Germany; Berlin-Brandenburg Center for Regenerative Therapies, Charité-Universitätsmedizin Berlin, Germany; Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Sara Checa
- Julius Wolff Institute, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Bettina M Willie
- Research Centre, Shriners Hospital for Children-Canada, Department of Pediatric Surgery, McGill University, Montreal, Canada; Julius Wolff Institute, Charité-Universitätsmedizin Berlin, Berlin, Germany.
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