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Sharkia R, Zalan A, Kessel A, Al-Shareef W, Zahalka H, Hengel H, Schöls L, Azem A, Mahajnah M. SCAPER-Related Autosomal Recessive Retinitis Pigmentosa with Intellectual Disability: Confirming and Extending the Phenotypic Spectrum and Bioinformatics Analyses. Genes (Basel) 2024; 15:791. [PMID: 38927727 PMCID: PMC11203295 DOI: 10.3390/genes15060791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2024] [Revised: 06/11/2024] [Accepted: 06/12/2024] [Indexed: 06/28/2024] Open
Abstract
Mutations in the gene SCAPER (S phase Cyclin A-Associated Protein residing in the Endoplasmic Reticulum) have recently been associated with retinitis pigmentosa (RP) and intellectual disability (ID). In 2011, a possible involvement of SCAPER in human diseases was discovered for the first time due to the identification of a homozygous mutation causing ID in an Iranian family. Later, five studies were published in 2019 that described patients with autosomal recessive syndromic retinitis pigmentosa (arRP) accompanied by ID and attention-deficit/hyperactivity disorder (ADHD). This present study describes three patients from an Arab consanguineous family in Israel with similar clinical features of the SCAPER syndrome. In addition, new manifestations of ocular symptoms, nystagmus, glaucoma, and elevator palsy, were observed. Genetic testing of the patients and both parents via whole-exome sequencing revealed the homozygous mutation c.2023-2A>G in SCAPER. Phenotypic and genotypic descriptions for all available cases described in the literature including our current three cases (37 cases) were carried out, in addition to a bioinformatics analysis for all the genetic variants that was undertaken. Our study confirms and extends the clinical manifestations of SCAPER-related disorders.
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Affiliation(s)
- Rajech Sharkia
- Unit of Human Biology and Genetics, The Triangle Regional Research and Development Center, Kafr Qara 3007500, Israel; (A.Z.); (W.A.-S.)
- Unit of Natural Sciences, Beit-Berl Academic College, Beit-Berl 4490500, Israel
| | - Abdelnaser Zalan
- Unit of Human Biology and Genetics, The Triangle Regional Research and Development Center, Kafr Qara 3007500, Israel; (A.Z.); (W.A.-S.)
- Baqa College, Al-Qasmi Street, 64, Baqa Al-Gharbia 3010000, Israel
| | - Amit Kessel
- Department of Biochemistry and Molecular Biology, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv 69978, Israel; (A.K.); (A.A.)
| | - Wasif Al-Shareef
- Unit of Human Biology and Genetics, The Triangle Regional Research and Development Center, Kafr Qara 3007500, Israel; (A.Z.); (W.A.-S.)
| | - Hazar Zahalka
- Child Development and Pediatric Neurology Service, Meuhedet—Northern Region, Hadera 38100, Israel;
| | - Holger Hengel
- Department of Neurology and Hertie-Institute for Clinical Brain Research, University of Tübingen, 72074 Tübingen, Germany; (H.H.); (L.S.)
- German Center of Neurodegenerative Diseases (DZNE), 72076 Tübingen, Germany
| | - Ludger Schöls
- Department of Neurology and Hertie-Institute for Clinical Brain Research, University of Tübingen, 72074 Tübingen, Germany; (H.H.); (L.S.)
- German Center of Neurodegenerative Diseases (DZNE), 72076 Tübingen, Germany
| | - Abdussalam Azem
- Department of Biochemistry and Molecular Biology, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv 69978, Israel; (A.K.); (A.A.)
| | - Muhammad Mahajnah
- The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel;
- Child Neurology and Development Center, Hillel Yaffe Medical Center, Hadera 38100, Israel
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2
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Piña F, Yan B, Hu J, Niwa M. Reticulons bind sphingolipids to activate the endoplasmic reticulum cell cycle checkpoint, the ER surveillance pathway. Cell Rep 2023; 42:113403. [PMID: 37979174 DOI: 10.1016/j.celrep.2023.113403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 12/09/2022] [Accepted: 10/23/2023] [Indexed: 11/20/2023] Open
Abstract
The inheritance of a functional endoplasmic reticulum (ER) is ensured by the ER stress surveillance (ERSU) pathway. Here, we made the unexpected discovery that reticulon 1 (Rtn1) and Yop1, well-known ER-curvature-generating proteins, each possess two sphingolipid-binding motifs within their transmembrane domains and that these motifs recognize the ER-stress-induced sphingolipid phytosphingosine (PHS), resulting in an ER inheritance block. Upon binding PHS, Rtn1/Yop1 accumulate on the ER tubule, poised to enter the emerging daughter cell, and cause its misdirection to the bud scars (i.e., previous cell division sites). Amino acid changes in the conserved PHS-binding motifs preclude Rtn1 or Yop1 from binding PHS and diminish their enrichment on the tubular ER, ultimately preventing the ER-stress-induced inheritance block. Conservation of these sphingolipid-binding motifs in human reticulons suggests that sphingolipid binding to Rtn1 and Yop1 represents an evolutionarily conserved mechanism that enables cells to respond to ER stress.
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Affiliation(s)
- Francisco Piña
- Division of Biological Sciences, Molecular Biology Section, University of California, San Diego, NSB#1, Rm. 5328, 9500 Gilman Drive, San Diego, CA 92093-0377, USA
| | - Bing Yan
- Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Rm. 6210, Chaoyang District, Beijing 100101, China
| | - Junjie Hu
- Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Rm. 6210, Chaoyang District, Beijing 100101, China
| | - Maho Niwa
- Division of Biological Sciences, Molecular Biology Section, University of California, San Diego, NSB#1, Rm. 5328, 9500 Gilman Drive, San Diego, CA 92093-0377, USA.
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Sheng L, Li J, Rao S, Yang Z, Huang Y. Cyclin-Dependent Kinase 5 Regulatory Subunit Associated Protein 3: Potential Functions and Implications for Development and Disease. Front Oncol 2021; 11:760429. [PMID: 34722315 PMCID: PMC8551632 DOI: 10.3389/fonc.2021.760429] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 09/27/2021] [Indexed: 12/24/2022] Open
Abstract
Cyclin-dependent kinase 5 (CDK5) regulatory subunit associated protein 3 (CDK5RAP3, also named as C53 or LZAP) was initially identified as a binding protein of CDK5 activator p35. To date, CDK5RAP3 has been reported to interact with a range of proteins involved in cellular events ranging from cell cycle, apoptosis, and invasion to UFMylation modification and endoplasmic reticulum stress. Owing to its crucial roles in cellular processes, CDK5RAP3 is demonstrated to be not only an active participant in embryonic and mammalian tissue development, but also a key regulator in the onset and progress of human cancers such as head and neck squamous cell carcinoma, gastric cancer, hepatocellular cancer, lung cancer, kidney cancer and breast cancer. Notwithstanding, the detailed function of CDK5RAP3 and its mechanism remain poorly defined. Here, we briefly described a history of the discovery of CDK5RAP3, and systematically overviewed its gene structural and distribution features. We also focused on the known functions of this protein and its implications for embryogenesis and tissue development, as well as diseases especially carcinoma. This review may facilitate to understand the molecular and functional basis of CDK5RAP3 and its association with development and disease, and provide a reasonable idea for novel therapeutic opportunities targeting CDK5RAP3.
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Affiliation(s)
- Linna Sheng
- Department of Pathophysiology, Basic Medical College of Nanchang University, Nanchang, China.,Graduate College of Nanchang University, Nanchang, China
| | - Jiaxuan Li
- Nanchang Joint Program, Queen Mary School, Nanchang University, Nanchang, China
| | - Shengfang Rao
- Department of Nuclear Medicine, Nanchang University Hospital, Nanchang, China
| | - Zhijun Yang
- Department of Pathophysiology, Basic Medical College of Nanchang University, Nanchang, China
| | - Yonghong Huang
- Department of Pathophysiology, Basic Medical College of Nanchang University, Nanchang, China
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Pandey S, Talukdar I, Jain BP, Tanti GK, Goswami SK. GSK3β and ERK regulate the expression of 78 kDa SG2NA and ectopic modulation of its level affects phases of cell cycle. Sci Rep 2017; 7:7555. [PMID: 28790387 PMCID: PMC5548716 DOI: 10.1038/s41598-017-08085-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 07/06/2017] [Indexed: 12/13/2022] Open
Abstract
Striatin and SG2NA are essential constituents of the multi-protein STRIPAK assembly harbouring protein phosphatase PP2A and several kinases. SG2NA has several isoforms generated by mRNA splicing and editing. While the expression of striatin is largely restricted to the striatum in brain, that of SG2NAs is ubiquitous. In NIH3T3 cells, only the 78 kDa isoform is expressed. When cells enter into the S phase, the level of SG2NA increases; reaches maximum at the G2/M phase and declines thereafter. Downregulation of SG2NA extends G1 phase and its overexpression extends G2. Ectopic expression of the 35 kDa has no effects on the cell cycle. Relative abundance of phospho-SG2NA is high in the microsome and cytosol and the nucleus but low in the mitochondria. Okadoic acid, an inhibitor of PP2A, increases the level of SG2NA which is further enhanced upon inhibition of proteasomal activity. Phospho-SG2NA is thus more stable than the dephosphorylated form. Inhibition of GSK3β by LiCl reduces its level, but the inhibition of ERK by PD98059 increases it. Thus, ERK decreases the level of phospho-SG2NA by inhibiting GSK3β. In cells depleted from SG2NA by shRNA, the levels of pGSK3β and pERK are reduced, suggesting that these kinases and SG2NA regulate each other's expression.
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Affiliation(s)
- Shweta Pandey
- School of Life Sciences, Jawaharlal Nehru University, 110067, New Delhi, India
| | - Indrani Talukdar
- School of Life Sciences, Jawaharlal Nehru University, 110067, New Delhi, India
| | - Buddhi P Jain
- School of Life Sciences, Jawaharlal Nehru University, 110067, New Delhi, India.,Department of Zoology, School of Life Sciences, Mahatma Gandhi Central University, Motihari, 845401, Bihar, India
| | - Goutam K Tanti
- School of Life Sciences, Jawaharlal Nehru University, 110067, New Delhi, India.,Department of Neurology, School of Medicine, Technical University of Munich, Munich, Germany
| | - Shyamal K Goswami
- School of Life Sciences, Jawaharlal Nehru University, 110067, New Delhi, India.
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Suppression of the novel ER protein Maxer by mutant ataxin-1 in Bergman glia contributes to non-cell-autonomous toxicity. EMBO J 2010; 29:2446-60. [PMID: 20531390 DOI: 10.1038/emboj.2010.116] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Accepted: 05/14/2010] [Indexed: 12/27/2022] Open
Abstract
Non-cell-autonomous effect of mutant proteins expressed in glia has been implicated in several neurodegenerative disorders, whereas molecules mediating the toxicity are currently not known. We identified a novel molecule named multiple alpha-helix protein located at ER (Maxer) downregulated by mutant ataxin-1 (Atx1) in Bergmann glia. Maxer is an endoplasmic reticulum (ER) membrane protein interacting with CDK5RAP3. Maxer anchors CDK5RAP3 to the ER and inhibits its function of Cyclin D1 transcription repression in the nucleus. The loss of Maxer eventually induces cell accumulation at G1 phase. It was also shown that mutant Atx1 represses Maxer and inhibits proliferation of Bergmann glia in vitro. Consistently, Bergmann glia are reduced in the cerebellum of mutant Atx1 knockin mice before onset. Glutamate-aspartate transporter reduction in Bergmann glia by mutant Atx1 and vulnerability of Purkinje cell to glutamate are both strengthened by Maxer knockdown in Bergmann glia, whereas Maxer overexpression rescues them. Collectively, these results suggest that the reduction of Maxer mediates functional deficiency of Bergmann glia, and might contribute to the non-cell-autonomous pathology of SCA1.
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Rosso L, Marques AC, Weier M, Lambert N, Lambot MA, Vanderhaeghen P, Kaessmann H. Birth and rapid subcellular adaptation of a hominoid-specific CDC14 protein. PLoS Biol 2008; 6:e140. [PMID: 18547142 PMCID: PMC2422853 DOI: 10.1371/journal.pbio.0060140] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2008] [Accepted: 04/28/2008] [Indexed: 11/18/2022] Open
Abstract
Gene duplication was prevalent during hominoid evolution, yet little is known about the functional fate of new ape gene copies. We characterized the CDC14B cell cycle gene and the functional evolution of its hominoid-specific daughter gene, CDC14Bretro. We found that CDC14B encodes four different splice isoforms that show different subcellular localizations (nucleus or microtubule-associated) and functional properties. A microtubular CDC14B variant spawned CDC14Bretro through retroposition in the hominoid ancestor 18-25 million years ago (Mya). CDC14Bretro evolved brain-/testis-specific expression after the duplication event and experienced a short period of intense positive selection in the African ape ancestor 7-12 Mya. Using resurrected ancestral protein variants, we demonstrate that by virtue of amino acid substitutions in distinct protein regions during this time, the subcellular localization of CDC14Bretro progressively shifted from the association with microtubules (stabilizing them) to an association with the endoplasmic reticulum. CDC14Bretro evolution represents a paradigm example of rapid, selectively driven subcellular relocalization, thus revealing a novel mode for the emergence of new gene function.
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Affiliation(s)
- Lia Rosso
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Ana Claudia Marques
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Manuela Weier
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Nelle Lambert
- Institut de Recherches en Biologie Humaine et Moleculaire (IRIBHM), University of Brussels, Brussels, Belgium
| | - Marie-Alexandra Lambot
- Institut de Recherches en Biologie Humaine et Moleculaire (IRIBHM), University of Brussels, Brussels, Belgium
| | - Pierre Vanderhaeghen
- Institut de Recherches en Biologie Humaine et Moleculaire (IRIBHM), University of Brussels, Brussels, Belgium
| | - Henrik Kaessmann
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
- * To whom correspondence should be addressed. E-mail:
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