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Kasaiyan M, Basiri M, Pajouhanfar S. The role of miRNA134 in pathogenesis and treatment of intractable epilepsy: a review article. NUCLEOSIDES, NUCLEOTIDES & NUCLEIC ACIDS 2024:1-16. [PMID: 38531025 DOI: 10.1080/15257770.2024.2331046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 03/11/2024] [Indexed: 03/28/2024]
Abstract
MicroRNA-134 (miRNA134) has emerged as a critical regulator in the pathogenesis of epilepsy, particularly in intractable cases resistant to conventional therapies. This review explores the multifaceted roles of miRNA134 in epileptogenesis, focusing on its influence on dendritic spine morphology and synaptic plasticity. Through its interactions with proteins such as LIM kinase 1 (LIMK1), Pumilio 2 (PUM2), and Tubby-like protein 1 (TULP1), miRNA134 modulates various molecular pathways implicated in epilepsy development. Preclinical studies have shown pro-mising results in targeting miRNA134 for mitigating seizure activity, highlighting its potential as a therapeutic target. Furthermore, miRNA134 holds promise as a biomarker for epilepsy diagnosis and prognosis, offering opportunities for personalized treatment approaches. However, further research is warranted to elucidate the precise mechanisms underlying miRNA134's effects and to translate these findings into clinical applications.
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Affiliation(s)
- Maniya Kasaiyan
- Division of Child Neurology, Pediatrics Department, Yale New Haven Hospital, Yale School of Medicine, New Haven, CT, USA
| | - Mohsen Basiri
- Department of Internal Medicine, Icahn School of Medicine at Mount Sinai, NYCHHC/Queens, New York City, NY, USA
| | - Sara Pajouhanfar
- Department of Pediatrics, St. Louis Children's Hospital, Washington University School of Medicine, St. Louis, MO, USA
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2
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Bano N, Aalam S, Bag SK. Tubby-like proteins (TLPs) transcription factor in different regulatory mechanism in plants: a review. PLANT MOLECULAR BIOLOGY 2022; 110:455-468. [PMID: 36255595 DOI: 10.1007/s11103-022-01301-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 07/14/2022] [Indexed: 06/16/2023]
Abstract
Tubby-like proteins (TLPs) transcription factors are found in single-celled to multi-cellular eukaryotes in the form of large multigene families. TLPs are identified through a specific signature of carboxyl terminal tubby domain, required for plasma membrane tethering and amino terminal F-box domain communicate as functional SCF-type E3 ligases. The comprehensive distribution of TLP gene family members in diverse species indicates some conserved functions of TLPs in multicellular organisms. Plant TLPs have higher gene members than animals and these members reported important role in multiple physiological and developmental processes and various environmental stress responses. Although the TLPs are suggested to be a putative transcription factors but their functional mechanism is not much clear. This review provides significant recent updates on TLP-mediated regulation with an insight into its functional roles, origin and evolution and also phytohormones related regulation to combat with various stresses and its involvement in adaptive stress response in crop plants.
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Affiliation(s)
- Nasreen Bano
- CSIR-National Botanical Research Institute (CSIR-NBRI), Rana Pratap Marg, Lucknow, 226001, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Shahre Aalam
- CSIR-National Botanical Research Institute (CSIR-NBRI), Rana Pratap Marg, Lucknow, 226001, India
| | - Sumit Kumar Bag
- CSIR-National Botanical Research Institute (CSIR-NBRI), Rana Pratap Marg, Lucknow, 226001, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
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3
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Lee CH, Kang GM, Kim MS. Mechanisms of Weight Control by Primary Cilia. Mol Cells 2022; 45:169-176. [PMID: 35387896 PMCID: PMC9001153 DOI: 10.14348/molcells.2022.2046] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 01/25/2022] [Accepted: 01/25/2022] [Indexed: 02/06/2023] Open
Abstract
A primary cilium, a hair-like protrusion of the plasma membrane, is a pivotal organelle for sensing external environmental signals and transducing intracellular signaling. An interesting linkage between cilia and obesity has been revealed by studies of the human genetic ciliopathies Bardet-Biedl syndrome and Alström syndrome, in which obesity is a principal manifestation. Mouse models of cell type-specific cilia dysgenesis have subsequently demonstrated that ciliary defects restricted to specific hypothalamic neurons are sufficient to induce obesity and hyperphagia. A potential mechanism underlying hypothalamic neuron cilia-related obesity is impaired ciliary localization of G protein-coupled receptors involved in the regulation of appetite and energy metabolism. A well-studied example of this is melanocortin 4 receptor (MC4R), mutations in which are the most common cause of human monogenic obesity. In the paraventricular hypothalamus neurons, a blockade of ciliary trafficking of MC4R as well as its downstream ciliary signaling leads to hyperphagia and weight gain. Another potential mechanism is reduced leptin signaling in hypothalamic neurons with defective cilia. Leptin receptors traffic to the periciliary area upon leptin stimulation. Moreover, defects in cilia formation hamper leptin signaling and actions in both developing and differentiated hypothalamic neurons. The list of obesity-linked ciliary proteins is expending and this supports a tight association between cilia and obesity. This article provides a brief review on the mechanism of how ciliary defects in hypothalamic neurons facilitate obesity.
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Affiliation(s)
- Chan Hee Lee
- Department of Biomedical Science, Hallym University, Chuncheon 24252, Korea
| | - Gil Myoung Kang
- Asan Institute for Life Sciences, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Min-Seon Kim
- Division of Endocrinology and Metabolism, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
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Song J, Fu Q, Liu G, Zhang C, Wang Y, Tao S, Liu R, Li Z. TULP3 silencing suppresses cell proliferation, migration and invasion in gastric cancer via the PTEN/Akt/Snail pathway. Cancer Treat Res Commun 2022; 31:100551. [PMID: 35344762 DOI: 10.1016/j.ctarc.2022.100551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 03/11/2022] [Accepted: 03/20/2022] [Indexed: 11/18/2022]
Abstract
BACKGROUND Tubby-like protein 3 (TULP3) is a member of the tubby family, has been related to the development of nervous system by gene knockout researches. Nevertheless, the role of TULP3 in the gastric cancer is not clear. METHODS Western blotting and real-time polymerase chain reaction (PCR) were employed for the quantitative detection of TULP3 expression in the gastric cancer and consecutive non-cancerous tissues, and gastric cancer cells. The roles of TULP3 in invasion, migration as well as proliferation of the gastric cancer cell in vivo and in vitro through utilizing colony formation, MTT, wound-healing, transwell and mouse xenograft model. Western blotting assay was implemented in order to clarify the potential molecular mechanisms. Furthermore, electron microscopy and western blot were evaluated TULP3 expression in gastric cancer patient extracted serum exosomes. RESULTS TULP3 expression levels were remarkably upregulated in the gastric cancer tissues and cells. Subsequent functional assays demonstrated that TULP3 downregulation suppressed invasion, migration as well as the proliferation of the gastric cancer cell. Mechanism assays depicted that the PTEN/Akt/Snail signaling pathway can inhibit invasion, migration as well as the proliferation of the gastric cancer cell via TULP3 silencing. Finally, we found that the expression of TULP3 could be determined in the extracted serum exosomes. The expression of TULP3 in gastric cancer group was higher in comparison with normal group. CONCLUSIONS Our results reveal that TULP3 might serve as a potential prognostic biomarker and therapeutic target for the treatment of gastric cancer.
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Affiliation(s)
- Jun Song
- Department of Laboratory Medicine, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, Anhui Province 241001, China
| | - Qingsheng Fu
- Department of Gastrointestinal Surgery, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, Anhui Province 241001, China
| | - Gang Liu
- Department of Gastrointestinal Surgery, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, Anhui Province 241001, China
| | - Chengxiong Zhang
- Department of Gastrointestinal Surgery, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, Anhui Province 241001, China
| | - Yingying Wang
- Department of Nuclear medicine, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, Anhui Province 241001, China
| | - Shaoneng Tao
- Department of Nuclear medicine, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, Anhui Province 241001, China.
| | - Rui Liu
- Department of Laboratory Medicine, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, Anhui Province 241001, China.
| | - Zhi Li
- Department of Rheumatology and Immunology, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, Anhui Province 241001, China.
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Hong JJ, Kim KE, Park SY, Bok J, Seo JT, Moon SJ. Differential Roles of Tubby Family Proteins in Ciliary Formation and Trafficking. Mol Cells 2021; 44:591-601. [PMID: 34462398 PMCID: PMC8424140 DOI: 10.14348/molcells.2021.0082] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 06/01/2021] [Accepted: 06/02/2021] [Indexed: 12/13/2022] Open
Abstract
Cilia are highly specialized organelles that extend from the cell membrane and function as cellular signaling hubs. Thus, cilia formation and the trafficking of signaling molecules into cilia are essential cellular processes. TULP3 and Tubby (TUB) are members of the tubby-like protein (TULP) family that regulate the ciliary trafficking of G-protein coupled receptors, but the functions of the remaining TULPs (i.e., TULP1 and TULP2) remain unclear. Herein, we explore whether these four structurally similar TULPs share a molecular function in ciliary protein trafficking. We found that TULP3 and TUB, but not TULP1 or TULP2, can rescue the defective cilia formation observed in TULP3-knockout (KO) hTERT RPE-1 cells. TULP3 and TUB also fully rescue the defective ciliary localization of ARL13B, INPP5E, and GPR161 in TULP3 KO RPE-1 cells, while TULP1 and TULP2 only mediate partial rescues. Furthermore, loss of TULP3 results in abnormal IFT140 localization, which can be fully rescued by TUB and partially rescued by TULP1 and TULP2. TUB's capacity for binding IFT-A is essential for its role in cilia formation and ciliary protein trafficking in RPE-1 cells, whereas its capacity for PIP2 binding is required for proper cilia length and IFT140 localization. Finally, chimeric TULP1 containing the IFT-A binding domain of TULP3 fully rescues ciliary protein trafficking, but not cilia formation. Together, these two TULP domains play distinct roles in ciliary protein trafficking but are insufficient for cilia formation in RPE-1 cells. In addition, TULP1 and TULP2 play other unknown molecular roles that should be addressed in the future.
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Affiliation(s)
- Julie J. Hong
- Department of Oral Biology, BK 21 FOUR Project, Yonsei University College of Dentistry, Seoul 03722, Korea
| | - Kyung Eun Kim
- Department of Oral Biology, BK 21 FOUR Project, Yonsei University College of Dentistry, Seoul 03722, Korea
| | - So Young Park
- Department of Oral Biology, BK 21 FOUR Project, Yonsei University College of Dentistry, Seoul 03722, Korea
| | - Jinwoong Bok
- Department of Anatomy, Yonsei University College of Medicine, Seoul 03722, Korea
| | - Jeong Taeg Seo
- Department of Oral Biology, BK 21 FOUR Project, Yonsei University College of Dentistry, Seoul 03722, Korea
| | - Seok Jun Moon
- Department of Oral Biology, BK 21 FOUR Project, Yonsei University College of Dentistry, Seoul 03722, Korea
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DiTirro D, Philbrook A, Rubino K, Sengupta P. The Caenorhabditis elegans Tubby homolog dynamically modulates olfactory cilia membrane morphogenesis and phospholipid composition. eLife 2019; 8:48789. [PMID: 31259686 PMCID: PMC6624019 DOI: 10.7554/elife.48789] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 06/21/2019] [Indexed: 12/13/2022] Open
Abstract
Plasticity in sensory signaling is partly mediated via regulated trafficking of signaling molecules to and from primary cilia. Tubby-related proteins regulate ciliary protein transport; however, their roles in remodeling cilia properties are not fully understood. We find that the C. elegans TUB-1 Tubby homolog regulates membrane morphogenesis and signaling protein transport in specialized sensory cilia. In particular, TUB-1 is essential for sensory signaling-dependent reshaping of olfactory cilia morphology. We show that compromised sensory signaling alters cilia membrane phosphoinositide composition via TUB-1-dependent trafficking of a PIP5 kinase. TUB-1 regulates localization of this lipid kinase at the cilia base in part via localization of the AP-2 adaptor complex subunit DPY-23. Our results describe new functions for Tubby proteins in the dynamic regulation of cilia membrane lipid composition, morphology, and signaling protein content, and suggest that this conserved family of proteins plays a critical role in mediating cilia structural and functional plasticity.
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Affiliation(s)
- Danielle DiTirro
- Department of Biology, Brandeis University, Waltham, United States
| | - Alison Philbrook
- Department of Biology, Brandeis University, Waltham, United States
| | - Kendrick Rubino
- Department of Biology, Brandeis University, Waltham, United States
| | - Piali Sengupta
- Department of Biology, Brandeis University, Waltham, United States
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Xu J, Xing S, Sun Q, Zhan C, Liu X, Zhang S, Wang X. The expression of a tubby-like protein from Malus domestica (MdTLP7) enhances abiotic stress tolerance in Arabidopsis. BMC PLANT BIOLOGY 2019; 19:60. [PMID: 30727953 PMCID: PMC6366083 DOI: 10.1186/s12870-019-1662-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 01/24/2019] [Indexed: 05/23/2023]
Abstract
BACKGROUND Tubby-like proteins (TLPs), characterized by a signature tubby domain, are widespread in plants and animals. To date, only plant TLPs involved in multifarious stress responses and male gametophyte development have been identified. However, studies on the molecular functions of plant TLPs are largely unknown. RESULTS In this investigation, the roles of a TLP from Malus domestica (MdTLP7) in response to abiotic stresses were characterized by expressing it in Arabidopsis. The expression of wild-type full-length MdTLP7 (FL) significantly increased the stress tolerance of Arabidopsis seedlings to osmotic, salt, cold and heat stress, while the expression of truncated MdTLP7 containing only the tubby domain (Tub) also showed some function. Located on a central α helix surrounded by 12 anti-parallel β strands in the tubby domain, the K190/R192 site may be involved in fixation to the plasma membrane, as shown by 3D homology modelling with animal TLPs. This site might play a crucial role in anti-stress functions since site-directed mutagenesis of MdTLP7 reduced stress tolerance. Subcellular localization showed that MdTLP7 was mainly localized in the plasma membrane in plant cells, suggesting that it might participate in the transduction of stress signals. CONCLUSIONS The results of this study showed that MdTLP7 could improve abiotic stress tolerance not only in bacteria but also in plants. The K190/R192 residues in the tubby domain were not only the plasma membrane binding site of MdTLP7 but also played a key role in stress tolerance. These results may provide a basis for further exploring the mechanism of anti-stress functioning and downstream target genes of plant TLPs.
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Affiliation(s)
- Jianing Xu
- College of Life Science, State Key Laboratory of Crop Biology, Shandong Agricultural University, Shandong Taian, 271018 People’s Republic of China
| | - Shanshan Xing
- College of Life Science, State Key Laboratory of Crop Biology, Shandong Agricultural University, Shandong Taian, 271018 People’s Republic of China
| | - Qinghua Sun
- College of Life Science, State Key Laboratory of Crop Biology, Shandong Agricultural University, Shandong Taian, 271018 People’s Republic of China
| | - Chunyan Zhan
- College of Life Science, State Key Laboratory of Crop Biology, Shandong Agricultural University, Shandong Taian, 271018 People’s Republic of China
| | - Xin Liu
- College of Life Science, State Key Laboratory of Crop Biology, Shandong Agricultural University, Shandong Taian, 271018 People’s Republic of China
| | - Shizhong Zhang
- College of Life Science, State Key Laboratory of Crop Biology, Shandong Agricultural University, Shandong Taian, 271018 People’s Republic of China
| | - Xiaoyun Wang
- College of Life Science, State Key Laboratory of Crop Biology, Shandong Agricultural University, Shandong Taian, 271018 People’s Republic of China
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8
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Wang M, Xu Z, Kong Y. The tubby-like proteins kingdom in animals and plants. Gene 2018; 642:16-25. [DOI: 10.1016/j.gene.2017.10.077] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2017] [Revised: 08/15/2017] [Accepted: 10/27/2017] [Indexed: 11/28/2022]
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9
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Monnereau C, Jansen PW, Tiemeier H, Jaddoe VWV, Felix JF. Influence of genetic variants associated with body mass index on eating behavior in childhood. Obesity (Silver Spring) 2017; 25:765-772. [PMID: 28245097 PMCID: PMC5496668 DOI: 10.1002/oby.21778] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 12/23/2016] [Accepted: 12/26/2016] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Childhood eating behaviors are associated with body mass index (BMI). Recent genome-wide association studies have identified many single-nucleotide polymorphisms (SNPs) associated with adult and childhood BMI. This study hypothesized that these SNPs also influence eating behavior. METHODS In a population-based prospective cohort study among 3,031 children (mean age [standard deviation]: 4.0 [0.1] years), two weighted genetic risk scores, based on 15 childhood and 97 adult BMI SNPs, and ten individual appetite- and/or satiety-related SNPs were tested for association with food fussiness, food responsiveness, enjoyment of food, satiety responsiveness, and slowness in eating. RESULTS The 15 SNP-based childhood BMI genetic risk score was not associated with the eating behavior subscales. The 97 SNP-based adult BMI genetic risk score was nominally associated with satiety responsiveness (β: -0.007 standard deviation, 95% confidence interval [CI] -0.013, 0.000). Of the 10 individual SNPs, rs11030104 in BDNF and rs10733682 in LMX1B were nominally associated with satiety responsiveness (β: -0.057 standard deviation, 95% CI -0.112, -0.002). CONCLUSIONS These findings do not strongly support the hypothesis that BMI-associated SNPs also influence eating behavior at this age. A potential role for BMI SNPs in satiety responsiveness during childhood was observed; however, no associations with the other eating behavior subscales were found.
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Affiliation(s)
- Claire Monnereau
- The Generation R Study Group, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
- Department of Epidemiology, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
- Department of Pediatrics, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - Pauline W Jansen
- Institute of Psychology, Erasmus University, Rotterdam, the Netherlands
- Department of Child and Adolescent Psychiatry/Psychology, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - Henning Tiemeier
- Department of Epidemiology, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
- Department of Child and Adolescent Psychiatry/Psychology, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
- Department of Psychiatry, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - Vincent W V Jaddoe
- The Generation R Study Group, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
- Department of Epidemiology, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
- Department of Pediatrics, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - Janine F Felix
- The Generation R Study Group, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
- Department of Epidemiology, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
- Department of Pediatrics, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
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Badgandi HB, Hwang SH, Shimada IS, Loriot E, Mukhopadhyay S. Tubby family proteins are adapters for ciliary trafficking of integral membrane proteins. J Cell Biol 2017; 216:743-760. [PMID: 28154160 PMCID: PMC5350516 DOI: 10.1083/jcb.201607095] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 11/25/2016] [Accepted: 01/09/2017] [Indexed: 01/19/2023] Open
Abstract
Trafficking of integral membrane proteins to cilia is poorly understood. Badgandi et al. show that tubby family proteins TULP3 and TUB act as general adapters for ciliary trafficking of structurally diverse integral membrane cargo like GCPRs and the polycystin 1/2 complex. The primary cilium is a paradigmatic organelle for studying compartmentalized signaling; however, unlike soluble protein trafficking, processes targeting integral membrane proteins to cilia are poorly understood. In this study, we determine that the tubby family protein TULP3 functions as a general adapter for ciliary trafficking of structurally diverse integral membrane cargo, including multiple reported and novel rhodopsin family G protein–coupled receptors (GPCRs) and the polycystic kidney disease–causing polycystin 1/2 complex. The founding tubby family member TUB also localizes to cilia similar to TULP3 and determines trafficking of a subset of these GPCRs to neuronal cilia. Using minimal ciliary localization sequences from GPCRs and fibrocystin (also implicated in polycystic kidney disease), we demonstrate these motifs to be sufficient and TULP3 dependent for ciliary trafficking. We propose a three-step model for TULP3/TUB-mediated ciliary trafficking, including the capture of diverse membrane cargo by the tubby domain in a phosphoinositide 4,5-bisphosphate (PI(4,5)P2)-dependent manner, ciliary delivery by intraflagellar transport complex A binding to the TULP3/TUB N terminus, and subsequent release into PI(4,5)P2-deficient ciliary membrane.
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Affiliation(s)
- Hemant B Badgandi
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Sun-Hee Hwang
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Issei S Shimada
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Evan Loriot
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390.,STARS Program, University of Texas Southwestern Medical Center, Dallas, TX 75390.,Jesuit College Preparatory School of Dallas, Dallas, TX 75244
| | - Saikat Mukhopadhyay
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
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11
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Kim JW, Kim HS, Kim SD, Park JY. Insulin Phosphorylates Tyrosine Residue 464 of Tub and Translocates Tubby into the Nucleus in HIRcB Cells. Endocrinol Metab (Seoul) 2014; 29:163-8. [PMID: 25031889 PMCID: PMC4091484 DOI: 10.3803/enm.2014.29.2.163] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Accepted: 02/17/2014] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND The tubby protein has a motif that might be relevant for its action in the insulin signaling pathway. Previous studies have indicated that tubby undergoes phosphorylation on tyrosine residues in response to several stimuli and is known to localize in the nucleus as well as in the plasma membrane. However, the relationship between phosphorylation and nuclear translocation is not well understood. Here, we report that insulin directly phosphorylates tubby, which translocates into the nucleus. METHODS The effects of insulin on Tubby were performed with Western blot. The immunoprecipitation and confocal microscopy were performed to prove phosphorylation and nuclear translocation. RESULTS Mutation study reveals that tyrosine residue 464 of tubby gene (Tub) is a phosphorylation site activated by insulin. In addition, major portions of tubby protein in the plasma membrane are translocated into the nucleus after insulin treatment. Tyrosine kinase inhibitor pretreatment blocked insulin-induced tubby translocation, suggesting that phosphorylation is important for nuclear translocation. Moreover, mutant tyrosine residue 464 did not translocate into the nucleus in respond to insulin. These findings demonstrate that insulin phosphorylates tyrosine residue 464 of Tub, and this event is important for insulin-induced tubby nuclear translocation. CONCLUSION Insulin phosphorylates tyrosine residue 464 of Tub and translocates tubby into the nuclei of HIRcB cells.
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Affiliation(s)
- Jin Wook Kim
- Department of Neurosurgery, Gachon University Gil Medical Center, Incheon, Korea
| | - Hyeon Soo Kim
- Department of Anatomy, Korea University College of Medicine, Seoul, Korea
| | - Sang Dae Kim
- Department of Neurosurgery, Korea University Ansan Hospital, Korea University College of Medicine, Ansan, Korea
| | - Jung Yul Park
- Department of Neurosurgery, Korea University Anam Hospital, Korea University College of Medicine, Seoul, Korea
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An obesity-like gene MdTLP7 from apple (Malus×domestica) enhances abiotic stress tolerance. Biochem Biophys Res Commun 2014; 445:394-7. [DOI: 10.1016/j.bbrc.2014.02.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 02/04/2014] [Indexed: 11/23/2022]
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13
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Wardhan V, Jahan K, Gupta S, Chennareddy S, Datta A, Chakraborty S, Chakraborty N. Overexpression of CaTLP1, a putative transcription factor in chickpea (Cicer arietinum L.), promotes stress tolerance. PLANT MOLECULAR BIOLOGY 2012; 79:479-93. [PMID: 22644439 DOI: 10.1007/s11103-012-9925-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Accepted: 05/10/2012] [Indexed: 05/15/2023]
Abstract
Dehydration is the most crucial environmental constraint on plant growth and development, and agricultural productivity. To understand the underlying mechanism of stress tolerance, and to identify proteins for improving such important trait, we screened the dehydration-responsive proteome of chickpea and identified a tubby-like protein, referred to as CaTLP1. The CaTLP1 was found to predominantly bind to double-stranded DNA but incapable of transcriptional activation. We investigated the gene structure and organization and demonstrated, for the first time, that CaTLP1 may be involved in osmotic stress response in plants. The transcripts are strongly expressed in vegetative tissues but weakly in reproductive tissues. CaTLP1 is upregulated by dehydration and high salinity, and by treatment with abscisic acid (ABA), suggesting that its stress-responsive function might be associated with ABA-dependent network. Overexpression of CaTLP1 in transgenic tobacco plants conferred dehydration, salinity and oxidative stress tolerance along with improved shoot and root architecture. Molecular genetic analysis showed differential expression of CaTLP1 under normal and stress condition, and its preferential expression in the nucleus might be associated with enhanced stress tolerance. Our work suggests important roles of CaTLP1 in stress response as well as in the regulation of plant development.
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Affiliation(s)
- Vijay Wardhan
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
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14
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Tulp1 is involved in specific photoreceptor protein transport pathways. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 723:783-9. [PMID: 22183407 DOI: 10.1007/978-1-4614-0631-0_100] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Abstract
The tubby mouse shows a tripartite syndrome characterized by maturity-onset obesity, blindness and deafness. The causative gene Tub is the founding member of a family of related proteins present throughout the animal and plant kingdoms, each characterized by a signature carboxy-terminal tubby domain. This domain consists of a β barrel enclosing a central α helix and binds selectively to specific membrane phosphoinositides. The vertebrate family of tubby-like proteins (TULPs) includes the founding member TUB and the related TULPs, TULP1 to TULP4. Tulp1 is expressed in the retina and mutations in TULP1 cause retinitis pigmentosa in humans; Tulp3 is expressed ubiquitously in the mouse embryo and is important in sonic hedgehog (Shh)-mediated dorso-ventral patterning of the spinal cord. The amino terminus of these proteins is diverse and directs distinct functions. In the best-characterized example, the TULP3 amino terminus binds to the IFT-A complex, a complex important in intraflagellar transport in the primary cilia, through a short conserved domain. Thus, the tubby family proteins seem to serve as bipartite bridges through their phosphoinositide-binding tubby and unique amino-terminal functional domains, coordinating multiple signaling pathways, including ciliary G-protein-coupled receptor trafficking and Shh signaling. Molecular studies on this functionally diverse protein family are beginning to provide us with remarkable insights into the tubby-mouse syndrome and other related diseases.
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Affiliation(s)
- Saikat Mukhopadhyay
- Department of Cell Regulation, Genentech Inc., South San Francisco, CA 94080, USA.
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16
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Stretton C, Litherland GJ, Moynihan A, Hajduch E, Hundal HS. Expression and modulation of TUB by insulin and thyroid hormone in primary rat and murine 3T3-L1 adipocytes. Biochem Biophys Res Commun 2009; 390:1328-33. [PMID: 19887065 DOI: 10.1016/j.bbrc.2009.10.147] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2009] [Accepted: 10/27/2009] [Indexed: 11/26/2022]
Abstract
tub encodes a protein of poorly understood function, but one implicated strongly in the control of energy balance and insulin sensitivity. Whilst tub expression is particularly prominent in neurones it is also detectable in extraneuronal tissues. We show here, for the first time, expression of TUB protein in rat adipocytes and the murine adipocyte model 3T3-L1 and demonstrate that insulin induces its tyrosine phosphorylation and association with the insulin receptor. TUB expression is regulated developmentally during adipogenic differentiation of 3T3-L1 cells and in response to cell treatment with thyroid hormone or induction of insulin resistance. TUB was upregulated 5- to 10-fold in adipocytes from obese Zucker rats and 3T3-L1 adipocytes that had been rendered insulin resistant, a response that could be antagonised by rosiglitasone, an insulin-sensitising drug. Our data are consistent with a previously unforeseen role for TUB in insulin signalling and fuel homeostasis in adipocytes.
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Affiliation(s)
- Clare Stretton
- Division of Molecular Physiology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
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17
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Wang Y, Nishina PM, Naggert JK. Degradation of IRS1 leads to impaired glucose uptake in adipose tissue of the type 2 diabetes mouse model TALLYHO/Jng. J Endocrinol 2009; 203:65-74. [PMID: 19587264 PMCID: PMC2853731 DOI: 10.1677/joe-09-0026] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The TALLYHO/Jng (TH) mouse strain is a polygenic model for type 2 diabetes (T2D) characterized by moderate obesity, impaired glucose tolerance and uptake, insulin resistance, and hyperinsulinemia. The goal of this study was to elucidate the molecular mechanisms responsible for the reduced glucose uptake and insulin resistance in the adipose tissue of this model. The translocation and localization of glucose transporter 4 (GLUT4) to the adipocyte plasma membrane were impaired in TH mice compared to control C57BL6/J (B6) mice. These defects were associated with decreased GLUT4 protein, reduced phosphatidylinositol 3-kinase activity, and alterations in the phosphorylation status of insulin receptor substrate 1 (IRS1). Activation of c-Jun N-terminal kinase 1/2, which can phosphorylate IRS1 on Ser307, was significantly higher in TH mice compared with B6 controls. IRS1 protein but not mRNA levels was found to be lower in TH mice than controls. Immunoprecipitation with anti-ubiquitin and western blot analysis of IRS1 protein revealed increased total IRS1 ubiquitination in adipose tissue of TH mice. Suppressor of cytokine signaling 1, known to promote IRS1 ubiquitination and subsequent degradation, was found at significantly higher levels in TH mice compared with B6. Immunohistochemistry showed that IRS1 colocalized with the 20S proteasome in proteasomal structures in TH adipocytes, supporting the notion that IRS1 is actively degraded. Our findings suggest that increased IRS1 degradation and subsequent impaired GLUT4 mobilization play a role in the reduced glucose uptake in insulin resistant TH mice. Since low-IRS1 levels are often observed in human T2D, the TH mouse is an attractive model to investigate mechanisms of insulin resistance and explore new treatments.
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Affiliation(s)
- Yun Wang
- The Jackson Laboratory, 600 Main Street, Bar Harbor, Maine 04609, USA
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Caberoy NB, Li W. Unconventional secretion of tubby and tubby-like protein 1. FEBS Lett 2009; 583:3057-62. [PMID: 19695251 DOI: 10.1016/j.febslet.2009.08.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2009] [Revised: 08/10/2009] [Accepted: 08/11/2009] [Indexed: 12/24/2022]
Abstract
Tubby-like proteins (Tulps) with no signal peptide have been characterized as cytoplasmic proteins with various intracellular functions, including binding to phosphatidylinositol-4,5-bisphosphate [PI(4,5)P(2)]. PI(4,5)P(2) has been implicated in unconventional secretion of fibroblast growth factor-2 without a signal peptide. Here, we show that all Tulps are expressed intracellularly and extracellularly. Tubby secretion is partially dependent on its PI(4,5)P(2)-binding activity with an essential secretory signal in the N-terminus. Pathogenic mutation in Tubby mice has no impact on tubby extracellular trafficking. Moreover, unconventional secretion of tubby and Tulp1 is independent of endoplasmic reticulum-Golgi pathway. These data implicate that Tulps may function extracellularly as well.
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Affiliation(s)
- Nora B Caberoy
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami School of Medicine, Miami, FL 33136, USA
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Norman RX, Ko HW, Huang V, Eun CM, Abler LL, Zhang Z, Sun X, Eggenschwiler JT. Tubby-like protein 3 (TULP3) regulates patterning in the mouse embryo through inhibition of Hedgehog signaling. Hum Mol Genet 2009; 18:1740-54. [PMID: 19286674 DOI: 10.1093/hmg/ddp113] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Tubby-like protein 3 (TULP3) is required for proper embryonic development in mice. Disruption of mouse Tulp3 results in morphological defects in the embryonic craniofacial regions, the spinal neural tube and the limbs. Here, we show that TULP3 functions as a novel negative regulator of Sonic hedgehog (Shh) signaling in the mouse. In Tulp3 mutants, ventral cell types in the lumbar neural tube, which acquire their identities in response to Shh signaling, are ectopically specified at the expense of dorsal cell types. Genetic epistasis experiments show that this ventralized phenotype occurs independently of Shh and the transmembrane protein Smoothened, but it is dependent on the transcription factor Gli2. The ventralized phenotype is also dependent on the kinesin II subunit Kif3A, which is required for intraflagellar transport and ciliogenesis. In addition, TULP3 is required for proper Shh-dependent limb patterning and for maintaining the correct balance between differentiation and proliferation in the neural tube. Finally, the localization of TULP3 to the tips of primary cilia raises the possibility that it regulates the Hedgehog pathway within this structure.
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Affiliation(s)
- Ryan X Norman
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
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Patterson VL, Damrau C, Paudyal A, Reeve B, Grimes DT, Stewart ME, Williams DJ, Siggers P, Greenfield A, Murdoch JN. Mouse hitchhiker mutants have spina bifida, dorso-ventral patterning defects and polydactyly: identification of Tulp3 as a novel negative regulator of the Sonic hedgehog pathway. Hum Mol Genet 2009; 18:1719-39. [PMID: 19223390 PMCID: PMC2671985 DOI: 10.1093/hmg/ddp075] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The mammalian Sonic hedgehog (Shh) signalling pathway is essential for embryonic development and the patterning of multiple organs. Disruption or activation of Shh signalling leads to multiple birth defects, including holoprosencephaly, neural tube defects and polydactyly, and in adults results in tumours of the skin or central nervous system. Genetic approaches with model organisms continue to identify novel components of the pathway, including key molecules that function as positive or negative regulators of Shh signalling. Data presented here define Tulp3 as a novel negative regulator of the Shh pathway. We have identified a new mouse mutant that is a strongly hypomorphic allele of Tulp3 and which exhibits expansion of ventral markers in the caudal spinal cord, as well as neural tube defects and preaxial polydactyly, consistent with increased Shh signalling. We demonstrate that Tulp3 acts genetically downstream of Shh and Smoothened (Smo) in neural tube patterning and exhibits a genetic interaction with Gli3 in limb development. We show that Tulp3 does not appear to alter expression or processing of Gli3, and we demonstrate that transcriptional regulation of other negative regulators (Rab23, Fkbp8, Thm1, Sufu and PKA) is not affected. We discuss the possible mechanism of action of Tulp3 in Shh-mediated signalling in light of these new data.
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Affiliation(s)
- Victoria L Patterson
- Mammalian Genetics Unit, MRC Harwell, Harwell Science and Innovation Campus, Oxon, UK
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21
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Grossman GH, Pauer GJT, Narendra U, Peachey NS, Hagstrom SA. Early synaptic defects in tulp1-/- mice. Invest Ophthalmol Vis Sci 2009; 50:3074-83. [PMID: 19218615 DOI: 10.1167/iovs.08-3190] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Mutations in the photoreceptor-specific tubby-like protein 1 (TULP1) underlie a form of autosomal recessive retinitis pigmentosa. To investigate the role of Tulp1 in the photoreceptor synapse, the authors examined the presynaptic and postsynaptic architecture and retinal function in tulp1(-/-) mice METHODS The authors used immunohistochemistry to examine tulp1(-/-) mice before retinal degeneration and made comparisons with wild-type (wt) littermates and retinal degeneration 10 (rd10) mice, another model of photoreceptor degeneration that has a comparable rate of degeneration. Retinal function was characterized with the use of electroretinography. RESULTS In wt mice, Tulp1 is localized to the photoreceptor synapse. In the tulp1(-/-) synapse, the spatial relationship between the ribbon-associated proteins Bassoon and Piccolo are disrupted, and few intact ribbons are present. Furthermore, bipolar cell dendrites are stunted. Comparable abnormalities are not seen in rd10 mice. The leading edge of the a-wave had normal kinetics in tulp1(-/-) mice but reduced gain in rd10 mice. The b-wave intensity-response functions of tulp1(-/-) mice are shifted to higher intensities than in wt mice, but those of rd10 mice are not. CONCLUSIONS Photoreceptor synapses and bipolar cell dendrites in tulp1(-/-) mice display abnormal structure and function. A malformation of the photoreceptor synaptic ribbon is likely the cause of the dystrophy in bipolar cell dendrites. The association of early-onset, severe photoreceptor degeneration preceded by synaptic abnormalities appears to represent a phenotype not previously described. Not only is Tulp1 critical for photoreceptor function and survival, it is essential for the proper development of the photoreceptor synapse.
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Affiliation(s)
- Gregory H Grossman
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, USA
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Snieder H, Wang X, Shiri-Sverdlov R, van Vliet-Ostaptchouk JV, Hofker MH, Perks U, Spector TD, O'Dell SD. TUB is a candidate gene for late-onset obesity in women. Diabetologia 2008; 51:54-61. [PMID: 17955208 DOI: 10.1007/s00125-007-0851-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2007] [Accepted: 09/24/2007] [Indexed: 10/22/2022]
Abstract
AIMS/HYPOTHESES We recently reported significant associations between BMI and three TUB single nucleotide polymorphisms (SNPs) in two Dutch cohorts enriched for type 2 diabetes. Here, we attempted a replication of these associations in a large population-based cohort of female twins comprehensively phenotyped for measures of general and central obesity. METHODS Two TUB SNPs (rs2272382, rs2272383) and a third (rs1528133), 22 kb distal to RIC3, were genotyped in 2694 Europid women from the St Thomas' UK Adult Twin Registry (Twins UK) (mean age +/- SD: 47.6 +/- 12.7 years; 42.8% postmenopausal). We explored the hypothesis that TUB is a candidate gene for late-onset obesity in humans through testing the interaction of the SNPs by menopausal status. RESULTS In the whole cohort, none of the three SNPs showed a significant main effect on measures of general or central obesity. However, for central obesity the rs2272382 SNP showed a significant interaction with menopausal status (p = 0.036). Postmenopausal women homozygous for the minor allele of rs2272382 showed significantly more general obesity (p = 0.022) and central obesity (p = 0.009) than carriers of the major allele. Differences (beta [95% CI]) between the two genotype groups were 0.92 kg/m2 (0.03-1.81) for BMI (p = 0.036), 2.73 cm (0.62-4.84) for waist circumference (p = 0.013) and 2.43% (0.27-4.60) for per cent central fat (p = 0.027). These associations were confirmed by a sibling transmission disequilibrium test for central obesity, waist circumference and per cent central fat. CONCLUSIONS/INTERPRETATION We have replicated associations of TUB SNP rs2272382 with measures of general and central obesity in normal postmenopausal women. These findings confirm TUB as a candidate gene for late-onset obesity in humans.
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Affiliation(s)
- H Snieder
- Unit of Genetic Epidemiology and Bioinformatics, Department of Epidemiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, P.O. Box 30.001, 9700 RB, Groningen, The Netherlands.
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Xi Q, Pauer GJT, Ball SL, Rayborn M, Hollyfield JG, Peachey NS, Crabb JW, Hagstrom SA. Interaction between the photoreceptor-specific tubby-like protein 1 and the neuronal-specific GTPase dynamin-1. Invest Ophthalmol Vis Sci 2007; 48:2837-44. [PMID: 17525220 PMCID: PMC3021943 DOI: 10.1167/iovs.06-0059] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Tubby-like proteins (TULPs) are a family of four proteins, two of which have been linked to neurosensory disease phenotypes. TULP1 is a photoreceptor-specific protein that is mutated in retinitis pigmentosa, an inherited retinal disease characterized by the degeneration of rod and cone photoreceptor cells. To investigate the function of TULP1 in maintaining the health of photoreceptors, the authors sought the identification of interacting proteins. METHODS Immunoprecipitation from retinal lysates, followed by liquid chromatography tandem mass spectrometry and in vitro binding assays, were used to identify TULP1 binding partners. RT-PCR was performed on total RNA from wild-type mouse retina to identify the Dynamin-1 isoform expressed in the retina. Immunocytochemistry was used to determine the localization of TULP1 and Dynamin-1 in photoreceptor cells. Electroretinography (ERG) and light microscopy were used to phenotype tulp1-/- mice at a young age. RESULTS Immunoprecipitation from retinal lysate identified Dynamin-1 as a possible TULP1 binding partner. GST pull-down assays further supported an interaction between TULP1 and Dynamin-1. In photoreceptor cells, Dynamin-1 and TULP1 colocalized primarily to the outer plexiform layer, where photoreceptor terminals synapse on second-order neurons and, to a lesser extent, to the inner segments, where polarized protein translocation occurs. ERG analyses in young tulp1-/- mice indicated a decreased b-wave at ages when the retina retained a full complement of photoreceptor cells. CONCLUSIONS These data indicated that TULP1 interacts with Dynamin-1 and suggested that TULP1 is involved in the vesicular trafficking of photoreceptor proteins, both at the nerve terminal during synaptic transmission and at the inner segment during protein translocation to the outer segment. These results also raised the possibility that normal synaptic function requires TULP1, and they motivate a closer look at synaptic architecture in the developing tulp1-/- retina.
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Affiliation(s)
- Quansheng Xi
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Gayle J. T. Pauer
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Sherry L. Ball
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio
- Cleveland Veterans Administration Medical Center, Cleveland, Ohio
| | - Mary Rayborn
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Joe G. Hollyfield
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio
- Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio
| | - Neal S. Peachey
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio
- Cleveland Veterans Administration Medical Center, Cleveland, Ohio
- Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio
| | - John W. Crabb
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio
- Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio
| | - Stephanie A. Hagstrom
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio
- Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio
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Inagaki Y, Mitsutake S, Igarashi Y. Identification of a nuclear localization signal in the retinitis pigmentosa-mutated RP26 protein, ceramide kinase-like protein. Biochem Biophys Res Commun 2006; 343:982-7. [PMID: 16581028 DOI: 10.1016/j.bbrc.2006.03.056] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2006] [Accepted: 03/08/2006] [Indexed: 11/24/2022]
Abstract
Retinitis pigmentosa (RP) is a genetically heterogeneous disease characterized by degeneration of the retina. A mutation in a new ceramide kinase (CERK) homologous gene, named CERK-like protein (CERKL), was found to cause autosomal recessive retinitis pigmentosa (RP26). Here, we show a point mutation of one of two putative nuclear localization signal (NLS) sequences inhibited the nuclear localization of the protein. Furthermore, the tetra-GFP-tagged NLS, which cannot passively enter the nucleus, was observed not only in the nucleus but also in the nucleolus. Our results provide the first evidence of the active nuclear import of CERKL and suggest that the identified NLS might be responsible for nucleolar retention of the protein. As recent studies have shown other RP-related proteins are localized in the nucleus or the nucleolus, our identification of NLS in CERKL suggests that CERKL likely plays important roles for retinal functions in the nucleus and the nucleolus.
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Affiliation(s)
- Yuichi Inagaki
- Department of Biomembrane and Biofunctional Chemistry, Graduate School of Pharmaceutical Science, Hokkaido University, Kita 12, Nishi 6, Kita-ku, Sapporo 060-0812, Japan
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Xi Q, Pauer GJ, Traboulsi EI, Hagstrom SA. Mutation screen of the TUB gene in patients with retinitis pigmentosa and Leber congenital amaurosis. Exp Eye Res 2006; 83:569-73. [PMID: 16643894 PMCID: PMC3023989 DOI: 10.1016/j.exer.2006.02.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2005] [Revised: 02/08/2006] [Accepted: 02/11/2006] [Indexed: 11/17/2022]
Abstract
TUB is the first identified member of the TULP family of four proteins with unknown function. A spontaneous mutation in murine tub causes retinal degeneration, obesity, and deafness. Mutations in another member of the TULP family, TULP1, are a cause of autosomal recessive retinitis pigmentosa (RP). These findings prompted us to investigate TUB as a candidate gene for RP and Leber congenital amaurosis (LCA). A mutation screen of the entire coding region of the TUB gene in 159 unrelated patients with autosomal recessive RP, 114 unrelated patients with simplex RP, and 21 unrelated patients with LCA uncovered 18 sequence variations. Of these, seven were missense mutations, six were isocoding changes, and five were intronic polymorphisms. All seven missense mutations were identified as heterozygous changes and no defect could be found in the other allele. None of the isocoding variants or intronic polymorphisms are predicted to create or destroy splice donor or acceptor sites based on splice-site prediction software. Although variant alleles of the TUB gene were found, none could be definitively associated with a specific retinal disease.
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Affiliation(s)
| | | | | | - Stephanie A. Hagstrom
- Corresponding author. Ophthalmic Research - i31, Cole Eye Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA. Tel.: +1 216 445 4133; fax: +1 216 445 3670. (S.A. Hagstrom)
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Xi Q, Pauer GJT, Marmorstein AD, Crabb JW, Hagstrom SA. Tubby-like protein 1 (TULP1) interacts with F-actin in photoreceptor cells. Invest Ophthalmol Vis Sci 2006; 46:4754-61. [PMID: 16303976 PMCID: PMC3026440 DOI: 10.1167/iovs.05-0693] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE TULP1 is a photoreceptor-specific protein of unknown function that, when mutated, can cause retinitis pigmentosa in humans and photoreceptor degeneration in mice. Toward a better understanding of the role of TULP1 in retinal disease, its subcellular localization was sought and the TULP1 protein binding partners identified. METHODS Immunocytochemistry and subcellular fractionation were used to determine the localization of TULP1 and actin in COS7 cells and photoreceptor cells. Immunoprecipitation from retinal lysates followed by liquid chromatography tandem mass spectrometry and in vitro binding assays was used to identify TULP1-binding partners. Phospholipid binding assays were performed with a commercially available kit. RESULTS TULP1 localizes at or near the plasma membrane and associates with the membranous fraction of COS7 cells, probably through binding phosphorylated phospholipids. In addition, TULP1 partitions to the aqueous phase during Triton X-114 extraction. Immunoprecipitation from retinal lysate identified F-actin as a possible TULP1-binding partner. Co-sedimentation assays further support an interaction between TULP1 and actin. In photoreceptor cells, actin and TULP1 colocalize at the inner segment, connecting cilium, and outer limiting membrane. CONCLUSIONS TULP1 is a cytoplasmic protein that associates with cellular membranes and the cytoskeleton. TULP1 and actin appear to interact and colocalize in photoreceptor cells of the retina. TULP1 may be involved in actin cytoskeletal functions such as protein trafficking that takes place at or near the plasma membrane from the inner segment through the connecting cilium into the outer segment of photoreceptor cells.
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Affiliation(s)
- Quansheng Xi
- Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio
| | | | - Alan D. Marmorstein
- Department of Ophthalmology and Vision Science, University of Arizona, Tucson, Arizona
| | - John W. Crabb
- Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio
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Mukhopadhyay A, Deplancke B, Walhout AJM, Tissenbaum HA. C. elegans tubby regulates life span and fat storage by two independent mechanisms. Cell Metab 2005; 2:35-42. [PMID: 16054097 DOI: 10.1016/j.cmet.2005.06.004] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2005] [Revised: 05/11/2005] [Accepted: 06/14/2005] [Indexed: 01/16/2023]
Abstract
In C. elegans, similar to in mammals, mutations in the tubby homolog, tub-1, promote increased fat deposition. Here, we show that mutation in tub-1 also leads to life span extension dependent on daf-16/FOXO. Interestingly, function of tub-1 in fat storage is independent of daf-16. A yeast two-hybrid screen identified a novel TUB-1 interaction partner (RBG-3); a RabGTPase-activating protein. Both TUB-1 and RBG-3 localize to overlapping neurons. Importantly, RNAi of rbg-3 decreases fat deposition in tub-1 mutants but does not affect life span. We demonstrate that TUB-1 is expressed in ciliated neurons and undergoes both dendritic and ciliary transport. Additionally, tub-1 mutants are chemotaxis defective. Thus, tub-1 may regulate fat storage either by modulating transport, sensing, or responding to signals in ciliated neurons. Taken together, we define a role for tub-1 in regulation of life span and show that tub-1 regulates life span and fat storage by two independent mechanisms.
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Abstract
The tubby mouse, which shows late-onset obesity and neurosensory deficits, arises from a mutation in the Tub gene. Tub shares homology with the genes for tubby-like proteins Tulp1, Tulp2 and Tulp3. Ablation of Tub, Tulp1 or Tulp3 causes disease phenotypes that are indicative of their importance in nervous-system function and development. Despite this importance, the biochemical functions of tubby-like proteins are only now beginning to be understood. At present, data indicate that tubby-like proteins might function as heterotrimeric-G-protein-responsive intracellular signalling factors, although an array of data also implicates them in other processes.
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Affiliation(s)
- Kilpatrick Carroll
- Department of Biochemistry and Molecular Biophysics, Columbia University, 701 West 168th Street, Room 712, New York, New York 10032, USA
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Ronshaugen M, McGinnis N, Inglis D, Chou D, Zhao J, McGinnis W. Structure and expression patterns of Drosophila TULP and TUSP, members of the tubby-like gene family. Mech Dev 2002; 117:209-15. [PMID: 12204260 DOI: 10.1016/s0925-4773(02)00211-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Tubby is a mouse gene that may provide a model for adult-onset obesity in humans. It is a member of a four gene family in mammals that collectively encode the Tubby-like proteins (TULPs), putative transcription factors which share similar 260 amino acid 'tubby domains' at their C-termini. The mammalian genome also encodes distant relatives of TULPs, which have been called TUSPs (tubby domain superfamily proteins). We have characterized the transcription unit of the single Drosophila TULP homolog, analyzed the expression pattern of the Drosophila TULP and TUSP genes, and determined the evolutionary relationships between the Drosophila proteins and members of the tubby domain superfamily in other organisms. Interestingly, like its mammalian homologs, Drosophila TULP is principally expressed in the embryonic central and peripheral nervous systems. This suggests that mammalian and Drosophila TULPs may possess some conserved functional properties in the nervous system. The Drosophila TUSP gene is also expressed in the central nervous system and olfactory organ but in few other peripheral sensory organs.
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Affiliation(s)
- Matthew Ronshaugen
- Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA 92093-0349, USA
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31
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Abstract
Mice that carry the recessive mutation tub develop neurosensory defects including retinal and cochlear degeneration, as well as maturity-onset obesity associated with insulin resistance. The biological function of the gene and the mechanism by which it induces its phenotypes are still unclear. In order to elucidate the pathways through which tub functions, in the current study, QTL modifiers were identified in an F2 intercross between (C57BL/6J- tub/tub and AKR/J-+/+) F1 hybrids (AKR intercross). The thickness of the outer nuclear layer of the retina and the number of photoreceptor nuclei were assessed in F2 mice homozygous for the tub mutation. A genome-wide scan revealed a significant linkage on chromosome 11 (named motr1) and two suggestive linkages on chromosomes 2 and 8. Interestingly, the same chromosome 2 region identified for the hearing modifier of tubby, the moth1 locus, showed a peak lod score of 2.3 for protection from retinal degeneration. This result suggests that the gene responsible for the QTL on chromosome 2 might be involved in a common pathway through which retinal and cochlear degeneration are induced in tubby mice.
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Affiliation(s)
- Akihiro Ikeda
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME 04609, USA
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32
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Ikeda A, Nishina PM, Naggert JK. The tubby-like proteins, a family with roles in neuronal development and function. J Cell Sci 2002; 115:9-14. [PMID: 11801719 DOI: 10.1242/jcs.115.1.9] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The identification of a mutation at the tubby (Tub) locus, which causes obesity and neurosensory degeneration, led to the discovery of the tubby-like proteins (TULPs). Tub and the genes that encode three tubby-like proteins (TULP1- TULP3) form a novel, small gene family that plays an important role in maintenance and function of neuronal cells during development and post-differentiation. Although exploration of the molecular function of these genes is still in its infancy, recent biochemical studies have provided ‘entry points’ into pathways whose elucidation will further our understanding of TULP action. In addition, mRNA expression and translocation of the TUB protein have been shown to be regulated by thyroid hormone and by G-protein-coupled receptor signaling, respectively. These latter findings may help to link the cellular function of TUB to known mechanisms for energy homeostasis.
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Affiliation(s)
- Akihiro Ikeda
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME 04609, USA
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33
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Li QZ, Wang CY, Shi JD, Ruan QG, Eckenrode S, Davoodi-Semiromi A, Kukar T, Gu Y, Lian W, Wu D, She JX. Molecular cloning and characterization of the mouse and human TUSP gene, a novel member of the tubby superfamily. Gene 2001; 273:275-84. [PMID: 11595174 DOI: 10.1016/s0378-1119(01)00582-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
We report here the cloning and characterization of a novel gene belonging to the tubby superfamily proteins (TUSP) in mouse and human. The mouse Tusp cDNA is 9120 bp in length and encodes a deduced protein of 1547 amino acids, while the human TUSP gene is 11,127 bp and encodes a deduced protein of 1544 amino acids. The human and mouse genes are 87% identical for their nucleotide sequences and 85% identical for their amino acid sequences. The protein sequences of these genes are 40-48% identical to other tubby family proteins at the C-terminal conserved 'tubby domain'. In addition, the TUSP proteins contain a tubby signature motif (FXGRVTQ), two bipartite nuclear localization signals (NLSs) at the C-terminal, two proline-rich regions, one WD40 repeat region and one suppressor of cytokines signaling domain. Transfection assay with green fluorescent protein-tagged TUSP expression constructs showed that the complete TUSP protein and the N-terminal portion of TUSP are localized in the cytoplasm but the C-terminal portion with the two NLSs produced distinct dots or spots localized in the cytoplasm. Northern blotting analysis showed that the major transcript with the complete coding sequence is expressed mainly in the brain, skeletal muscle, testis and kidney. Radiation hybrid mapping localized the mouse gene to chromosome 17q13 and the human TUSP gene to chromosome 6q25-q26 near the type 1 diabetes gene IDDM5. However, association analysis in diabetic families with a polymorphic microsatellite marker did not show any evidence for association between TUSP and type 1 diabetes. The precise biological function of the tubby superfamily genes is still unknown; the highly conserved tubby domain in different species, however, suggests that these proteins must have fundamental biological functions in a wide range of multi-cellular organisms.
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MESH Headings
- Adaptor Proteins, Signal Transducing
- Alternative Splicing
- Amino Acid Sequence
- Animals
- Blotting, Northern
- Cell Line
- Chromosome Mapping
- Chromosomes, Human, Pair 6/genetics
- Cloning, Molecular
- Cytoplasm/metabolism
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- Diabetes Mellitus/genetics
- Dinucleotide Repeats/genetics
- Female
- Gene Expression
- Genes/genetics
- Green Fluorescent Proteins
- Humans
- Intracellular Signaling Peptides and Proteins
- Luminescent Proteins/genetics
- Luminescent Proteins/metabolism
- Male
- Mice
- Molecular Sequence Data
- Phylogeny
- Polymorphism, Genetic
- Proteins/genetics
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/metabolism
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Tissue Distribution
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Affiliation(s)
- Q Z Li
- Department of Pathology, Immunology and Laboratory Medicine, Center for Mammalian Genetics and Diabetes Center of Excellence, College of Medicine, University of Florida, Gainesville, FL 32610, USA
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Heikenwälder MF, Koritschoner NP, Pajer P, Chaboissier MC, Kurz SM, Briegel KJ, Bartunek P, Zenke M. Molecular cloning, expression and regulation of the avian tubby-like protein 1 (tulp1) gene. Gene 2001; 273:131-9. [PMID: 11483369 DOI: 10.1016/s0378-1119(01)00578-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The tubby-like protein 1 (tulp1) gene is a member of the tubby multigene family which includes tub, tulp1, tulp2 and tulp3. Human and mouse tulp1 genes were cloned and mutations in tulp1 have been implicated in retinitis pigmentosa in man. Here we report on the cDNA cloning of the chicken tulp1 homologue and its protein product deduced from the nucleotide sequence. The chicken Tulp1 protein comprises 358 amino acids with a calculated molecular mass of 40 kDa. The overall structure of Tub and Tulp proteins, exemplified by the highly conserved C-terminal domain of 255 amino acids and the signature motif KLACE, is also preserved in chicken Tulp1. Phylogenetic analysis demonstrates that chicken tulp1 cDNA and protein are closely related to human and mouse tulp1. In addition, chicken tulp1 mRNA is abundantly expressed in retina similar to tulp1 expression in human and mouse. Two tulp1-specific transcripts of 2 and 3 kb in size were identified that showed differential regulation during embryonic and postnatal development. Finally, tulp1 mRNA was found to be expressed in chicken erythroid cells and upregulated by ligand-activated thyroid hormone receptor (TR alpha/c-erbA).
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Affiliation(s)
- M F Heikenwälder
- Max-Delbrück-Center for Molecular Medicine, MDC, Robert-Rössle Strasse 10, D-13122 Berlin, Germany
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Santagata S, Boggon TJ, Baird CL, Gomez CA, Zhao J, Shan WS, Myszka DG, Shapiro L. G-protein signaling through tubby proteins. Science 2001; 292:2041-50. [PMID: 11375483 DOI: 10.1126/science.1061233] [Citation(s) in RCA: 289] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Dysfunction of the tubby protein results in maturity-onset obesity in mice. Tubby has been implicated as a transcription regulator, but details of the molecular mechanism underlying its function remain unclear. Here we show that tubby functions in signal transduction from heterotrimeric GTP-binding protein (G protein)-coupled receptors. Tubby localizes to the plasma membrane by binding phosphatidylinositol 4,5-bisphosphate through its carboxyl terminal "tubby domain." X-ray crystallography reveals the atomic-level basis of this interaction and implicates tubby domains as phosphorylated-phosphatidyl- inositol binding factors. Receptor-mediated activation of G protein alphaq (Galphaq) releases tubby from the plasma membrane through the action of phospholipase C-beta, triggering translocation of tubby to the cell nucleus. The localization of tubby-like protein 3 (TULP3) is similarly regulated. These data suggest that tubby proteins function as membrane-bound transcription regulators that translocate to the nucleus in response to phosphoinositide hydrolysis, providing a direct link between G-protein signaling and the regulation of gene expression.
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MESH Headings
- Active Transport, Cell Nucleus
- Adaptor Proteins, Signal Transducing
- Amino Acid Sequence
- Animals
- Cell Membrane/metabolism
- Cell Nucleus/metabolism
- Cells, Cultured
- Crystallography, X-Ray
- GTP-Binding Protein alpha Subunits, Gq-G11
- Gene Expression Regulation
- Heterotrimeric GTP-Binding Proteins/metabolism
- Humans
- Intercellular Signaling Peptides and Proteins
- Intracellular Signaling Peptides and Proteins
- Isoenzymes/metabolism
- Membrane Lipids/metabolism
- Mice
- Models, Biological
- Molecular Sequence Data
- Nuclear Localization Signals
- Obesity/genetics
- Obesity/metabolism
- Phosphatidylinositol 4,5-Diphosphate/metabolism
- Phosphatidylinositol Phosphates/metabolism
- Phospholipase C beta
- Phosphorylation
- Protein Structure, Tertiary
- Proteins/chemistry
- Proteins/genetics
- Proteins/metabolism
- Receptor, Serotonin, 5-HT2C
- Receptors, Muscarinic/metabolism
- Receptors, Serotonin/metabolism
- Recombinant Fusion Proteins/metabolism
- Signal Transduction
- Transcription Factors/chemistry
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Type C Phospholipases/metabolism
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Affiliation(s)
- S Santagata
- Ruttenberg Cancer Center, Structural Biology Program, Department of Physiology and Biophysics, Mount Sinai School of Medicine of New York University, 1425 Madison Avenue New York, NY 10029, USA
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