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Motipally SI, Kolson DR, Guan T, Kolandaivelu S. Aberrant lipid accumulation and retinal pigment epithelium dysfunction in PRCD-deficient mice. Exp Eye Res 2024; 246:110016. [PMID: 39098587 DOI: 10.1016/j.exer.2024.110016] [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: 05/30/2024] [Revised: 07/24/2024] [Accepted: 07/30/2024] [Indexed: 08/06/2024]
Abstract
Progressive Rod-Cone Degeneration (PRCD) is an integral membrane protein found in photoreceptor outer segment (OS) disc membranes and its function remains unknown. Mutations in Prcd are implicated in Retinitis pigmentosa (RP) in humans and multiple dog breeds. PRCD-deficient models exhibit decreased levels of cholesterol in the plasma. However, potential changes in the retinal cholesterol remain unexplored. In addition, impaired phagocytosis observed in these animal models points to potential deficits in the retinal pigment epithelium (RPE). Here, using a Prcd-/- murine model we investigated the alterations in the retinal cholesterol levels and impairments in the structural and functional integrity of the RPE. Lipidomic and immunohistochemical analyses show a 5-fold increase in the levels of cholesteryl esters (C.Es) and lipid deposits in the PRCD-deficient retina, respectively, indicating alterations in total retinal cholesterol. Furthermore, the RPE of Prcd-/- mice exhibit a 1.7-fold increase in the expression of lipid transporter gene ATP-binding cassette transporter A1 (Abca1). Longitudinal fundus and spectral domain optical coherence tomography (SD-OCT) examinations showed focal lesions and RPE hyperreflectivity. Strikingly, the RPE of Prcd-/- mice exhibited age-related pathological features such as lipofuscin accumulation, Bruch's membrane (BrM) deposits and drusenoid focal deposits, mirroring an Age-related Macular Degeneration (AMD)-like phenotype. We propose that the extensive lipofuscin accumulation likely impairs lysosomal function, leading to the defective phagocytosis observed in Prcd-/- mice. Our findings support the dysregulation of retinal cholesterol homeostasis in the absence of PRCD. Further, we demonstrate that progressive photoreceptor degeneration in Prcd-/- mice is accompanied by progressive structural and functional deficits in the RPE, which likely exacerbates vision loss over time.
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Affiliation(s)
- Sree I Motipally
- Department of Neuroscience, Rockefeller Neuroscience Institute, 33 Medical Centre Drive, West Virginia University, Morgantown, WV, 26506, USA; Department of Ophthalmology and Visual Sciences, One Medical Center Drive, ERMA 2nd Floor, West Virginia University, Morgantown, WV, 26505-9193, USA
| | - Douglas R Kolson
- Department of Ophthalmology and Visual Sciences, One Medical Center Drive, ERMA 2nd Floor, West Virginia University, Morgantown, WV, 26505-9193, USA
| | - Tongju Guan
- Department of Ophthalmology and Visual Sciences, One Medical Center Drive, ERMA 2nd Floor, West Virginia University, Morgantown, WV, 26505-9193, USA; Department of Biochemistry and Molecular Medicine, 64 Medical Center Drive, West Virginia University, Morgantown, WV, 26505-9193, USA
| | - Saravanan Kolandaivelu
- Department of Ophthalmology and Visual Sciences, One Medical Center Drive, ERMA 2nd Floor, West Virginia University, Morgantown, WV, 26505-9193, USA; Department of Biochemistry and Molecular Medicine, 64 Medical Center Drive, West Virginia University, Morgantown, WV, 26505-9193, USA.
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Motipally SI, Kolson DR, Guan T, Kolandaivelu S. Aberrant lipid accumulation and retinal pigmental epithelium dysfunction in PRCD-deficient mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.08.584131. [PMID: 38558979 PMCID: PMC10979840 DOI: 10.1101/2024.03.08.584131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Progressive Rod-Cone Degeneration (PRCD) is an integral membrane protein found in photoreceptor outer segment (OS) disc membranes and its function remains unknown. Mutations in Prcd are implicated in Retinitis pigmentosa (RP) in humans and multiple dog breeds. PRCD-deficient models exhibit decreased levels of cholesterol in the plasma. However, potential changes in the retinal cholesterol remain unexplored. In addition, impaired phagocytosis observed in these animal models points to potential deficits in the retinal pigment epithelium (RPE). Here, using a Prcd -/- murine model we investigated the alterations in the retinal cholesterol levels and impairments in the structural and functional integrity of the RPE. Lipidomic and immunohistochemical analyses show a 5-fold increase in the levels of cholesteryl esters (C.Es) and accumulation of neutral lipids in the PRCD-deficient retina, respectively, indicating alterations in total retinal cholesterol. Longitudinal fundus and spectral domain optical coherence tomography (SD-OCT) examinations showed focal lesions and RPE hyperreflectivity. Strikingly, the RPE of Prcd -/- mice exhibited age-related pathological features such as neutral lipid deposits, lipofuscin accumulation, Bruch's membrane (BrM) thickening and drusenoid focal deposits, mirroring an Age-related Macular Degeneration (AMD)-like phenotype. We propose that the extensive lipofuscin accumulation likely impairs lysosomal function, leading to the defective phagocytosis observed in Prcd -/- mice. Our findings support the dysregulation of retinal cholesterol homeostasis in the absence of PRCD. Further, we demonstrate that progressive photoreceptor degeneration in Prcd -/- mice is accompanied by progressive structural and functional deficits in the RPE, which likely exacerbates vision loss over time.
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Motipally SI, Myers B, Sechrest ER, Sokolov D, Murphy J, Kolandaivelu S. A Modified Acyl-RAC Method of Isolating Retinal Palmitoyl Proteome for Subsequent Detection through LC-MS/MS. Bio Protoc 2023; 13:e4654. [PMID: 37113337 PMCID: PMC10127047 DOI: 10.21769/bioprotoc.4654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 01/19/2023] [Accepted: 03/01/2023] [Indexed: 04/29/2023] Open
Abstract
Palmitoylation is a unique and reversible posttranslational lipid modification (PTM) that plays a critical role in many cellular events, including protein stability, activity, membrane association, and protein-protein interactions. The dynamic nature of palmitoylation dictates the efficient sorting of various retinal proteins to specific subcellular compartments. However, the underlying mechanism through which palmitoylation supports efficient protein trafficking in the retina remains unclear. Recent studies show that palmitoylation can also function as a signaling PTM, underlying epigenetic regulation and homeostasis in the retina. Efficient isolation of retinal palmitoyl proteome will pave the way to a better understanding of the role(s) for palmitoylation in visual function. The standard methods for detecting palmitoylated proteins employ 3H- or 14C-radiolabeled palmitic acid and have many limitations, including poor sensitivity. Relatively recent studies use thiopropyl Sepharose 6B resin, which offers efficient detection of palmitoylated proteome but is now discontinued from the market. Here, we describe a modified acyl resin-assisted capture (Acyl-RAC) method using agarose S3 high-capacity resin to purify palmitoylated proteins from the retina and other tissues, which is greatly compatible with downstream processing by LC-MS/MS. Unlike other palmitoylation assays, the present protocol is easy to perform and cost-effective. Graphical abstract.
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Affiliation(s)
- Sree I Motipally
- Department of Ophthalmology and Visual Sciences, Eye Institute, One Medical Center Drive, West Virginia University, Morgantown, WV 26506, USA
- Department of Neuroscience, One Medical Center Drive, West Virginia University, Morgantown, WV 26506, USA
| | - Boyden Myers
- Department of Ophthalmology and Visual Sciences, Eye Institute, One Medical Center Drive, West Virginia University, Morgantown, WV 26506, USA
| | - Emily R Sechrest
- Department of Ophthalmology and Visual Sciences, Eye Institute, One Medical Center Drive, West Virginia University, Morgantown, WV 26506, USA
| | - David Sokolov
- Department of Ophthalmology and Visual Sciences, Eye Institute, One Medical Center Drive, West Virginia University, Morgantown, WV 26506, USA
| | - Joseph Murphy
- Department of Ophthalmology and Visual Sciences, Eye Institute, One Medical Center Drive, West Virginia University, Morgantown, WV 26506, USA
| | - Saravanan Kolandaivelu
- Department of Ophthalmology and Visual Sciences, Eye Institute, One Medical Center Drive, West Virginia University, Morgantown, WV 26506, USA
- Department of Biochemistry and Molecular Medicine, 64 Medical Center Drive, HSC North, West Virginia University, Morgantown, WV 26506, USA
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Starr CR, Gorbatyuk MS. Posttranslational modifications of proteins in diseased retina. Front Cell Neurosci 2023; 17:1150220. [PMID: 37066080 PMCID: PMC10097899 DOI: 10.3389/fncel.2023.1150220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 03/13/2023] [Indexed: 04/03/2023] Open
Abstract
Posttranslational modifications (PTMs) are known to constitute a key step in protein biosynthesis and in the regulation of protein functions. Recent breakthroughs in protein purification strategies and current proteome technologies make it possible to identify the proteomics of healthy and diseased retinas. Despite these advantages, the research field identifying sets of posttranslationally modified proteins (PTMomes) related to diseased retinas is significantly lagging, despite knowledge of the major retina PTMome being critical to drug development. In this review, we highlight current updates regarding the PTMomes in three retinal degenerative diseases-namely, diabetic retinopathy (DR), glaucoma, and retinitis pigmentosa (RP). A literature search reveals the necessity to expedite investigations into essential PTMomes in the diseased retina and validate their physiological roles. This knowledge would accelerate the development of treatments for retinal degenerative disorders and the prevention of blindness in affected populations.
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Affiliation(s)
| | - Marina S. Gorbatyuk
- Department of Optometry and Vision Science, University of Alabama at Birmingham, Birmingham, AL, United States
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Motipally SI, Kolandaivelu S. Absence of PRCD Leads to Dysregulation in Lipid Homeostasis Resulting in Disorganization of Photoreceptor Outer Segment Structure. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1415:389-394. [PMID: 37440062 DOI: 10.1007/978-3-031-27681-1_57] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
The outer segments of photoreceptors are specialized sensory cilia crucial for light detection. Any disruption that alters outer segment morphology can impair photoreceptor function and therefore vision. Progressive rod-cone degeneration (PRCD) is an integral membrane protein exclusively present in the photoreceptor OS with an unknown function. Multiple mutations in PRCD are linked with retinitis pigmentosa. The most common PRCD mutation observed in both human and multiple dog breeds, PRCD-C2Y, lacks the lipid modification "palmitoylation," which is crucial for protein stability and trafficking to the OS. Previous studies including ours show impaired disc morphogenesis and rhodopsin distributions in the absence of PRCD, but the precise role of PRCD in maintaining OS structure and function remains unclear. In this chapter, we discuss the potential role of PRCD in the maintenance of photoreceptor OS structural and functional integrity.
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Affiliation(s)
- Sree I Motipally
- Departments of Neuroscience and Biochemistry, Robert C. Byrd Health Sciences Centre, WVU Eye Institute, Morgantown, WV, USA
| | - Saravanan Kolandaivelu
- Departments of Ophthalmology, Visual Sciences and Biochemistry, Robert C. Byrd Health Sciences Centre, WVU Eye Institute, Morgantown, WV, USA.
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Myers B, Sechrest ER, Hamner G, Motipally SI, Murphy J, Kolandaivelu S. R17C Mutation in Photoreceptor Disc-Specific Protein, PRCD, Results in Additional Lipidation Altering Protein Stability and Subcellular Localization. Int J Mol Sci 2022; 23:ijms231810802. [PMID: 36142714 PMCID: PMC9503786 DOI: 10.3390/ijms231810802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 09/07/2022] [Accepted: 09/09/2022] [Indexed: 11/16/2022] Open
Abstract
Progressive rod-cone degeneration (PRCD) is a photoreceptor outer segment (OS) disc-specific protein essential for maintaining OS structures while contributing to rhodopsin packaging densities and distribution in disc membranes. Previously, we showed PRCD undergoing palmitoylation at the sole cysteine (Cys2), where a mutation linked with retinitis pigmentosa (RP) in humans and dogs demonstrates the importance of palmitoylation for protein stability and trafficking to the OS. We demonstrate a mutation, in the polybasic region (PBR) of PRCD (Arg17Cys) linked with RP where an additional lipidation is observed through acyl-RAC. Immunolocalization of transiently expressed R17C in hRPE1 cells depicts similar characteristics to wild-type PRCD; however, a double mutant lacking endogenous palmitoylation at Cys2Tyr with Arg17Cys is comparable to the C2Y protein as both aggregate, mislocalized to the subcellular compartments within the cytoplasm. Subretinal injection of PRCD mutant constructs followed by electroporation in murine retina exhibit mislocalization in the inner segment. Despite being additionally lipidated and demonstrating strong membrane association, the mutation in the PBR affects protein stability and localization to the OS. Acylation within the PBR alone neither compensates for protein stability nor trafficking, revealing defects in the PBR likely lead to dysregulation of PRCD protein associated with blinding diseases.
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Affiliation(s)
- Boyden Myers
- Department of Ophthalmology and Visual Sciences, Eye Institute, One Medical Center Drive, West Virginia University, Morgantown, WV 26506, USA
| | - Emily R. Sechrest
- Department of Ophthalmology and Visual Sciences, Eye Institute, One Medical Center Drive, West Virginia University, Morgantown, WV 26506, USA
| | - Gabrielle Hamner
- Department of Ophthalmology and Visual Sciences, Eye Institute, One Medical Center Drive, West Virginia University, Morgantown, WV 26506, USA
| | - Sree I. Motipally
- Department of Ophthalmology and Visual Sciences, Eye Institute, One Medical Center Drive, West Virginia University, Morgantown, WV 26506, USA
- Department of Neurosciences, One Medical Center Drive, West Virginia University, Morgantown, WV 26506, USA
| | - Joseph Murphy
- Department of Ophthalmology and Visual Sciences, Eye Institute, One Medical Center Drive, West Virginia University, Morgantown, WV 26506, USA
| | - Saravanan Kolandaivelu
- Department of Ophthalmology and Visual Sciences, Eye Institute, One Medical Center Drive, West Virginia University, Morgantown, WV 26506, USA
- Department of Biochemistry and Molecular Medicine, One Medical Center Drive, West Virginia University, Morgantown, WV 26506, USA
- Correspondence:
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Abstract
DHHC3 is a DHHC-family palmitoyl acyltransferase that is responsible for many mammalian palmitoylation events. By regulating the posttranslational modification of its specific substrates, DHHC3 has shown a strong protumor effect in various cancers. In this review, the authors introduce the research progress of DHHC3 as a new antitumor target through the expression of DHHC3 in patients with tumors, substrate proteins and potential mechanisms. Recent advances in the search for protein structures and inhibitors are also reviewed. Several design strategies to facilitate the optimization of the process of drug design based on DHHC3 are also discussed.
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Lee JW, Hur J, Kwon YW, Chae CW, Choi JI, Hwang I, Yun JY, Kang JA, Choi YE, Kim YH, Lee SE, Lee C, Jo DH, Seok H, Cho BS, Baek SH, Kim HS. KAI1(CD82) is a key molecule to control angiogenesis and switch angiogenic milieu to quiescent state. J Hematol Oncol 2021; 14:148. [PMID: 34530889 PMCID: PMC8444549 DOI: 10.1186/s13045-021-01147-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 08/25/2021] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Little is known about endogenous inhibitors of angiogenic growth factors. In this study, we identified a novel endogenous anti-angiogenic factor expressed in pericytes and clarified its underlying mechanism and clinical significance. METHODS Herein, we found Kai1 knockout mice showed significantly enhanced angiogenesis. Then, we investigated the anti-angiogenic roll of Kai1 in vitro and in vivo. RESULTS KAI1 was mainly expressed in pericytes rather than in endothelial cells. It localized at the membrane surface after palmitoylation by zDHHC4 enzyme and induced LIF through the Src/p53 pathway. LIF released from pericytes in turn suppressed angiogenic factors in endothelial cells as well as in pericytes themselves, leading to inhibition of angiogenesis. Interestingly, KAI1 had another mechanism to inhibit angiogenesis: It directly bound to VEGF and PDGF and inhibited activation of their receptors. In the two different in vivo cancer models, KAI1 supplementation significantly inhibited tumor angiogenesis and growth. A peptide derived from the large extracellular loop of KAI1 has been shown to have anti-angiogenic effects to block the progression of breast cancer and retinal neovascularization in vivo. CONCLUSIONS KAI1 from PC is a novel molecular regulator that counterbalances the effect of angiogenic factors.
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Affiliation(s)
- Jin-Woo Lee
- National Research Laboratory for Stem Cell Niche, Center for Medical Innovation, Seoul National University Hospital, Seoul, Republic of Korea
- Center of Cell- and Bio-Therapy (CBT), Seoul National University Hospital, Seoul, Republic of Korea
| | - Jin Hur
- Department of Convergence Medicine, Pusan National University School of Medicine, Yangsan, Republic of Korea
| | - Yoo-Wook Kwon
- National Research Laboratory for Stem Cell Niche, Center for Medical Innovation, Seoul National University Hospital, Seoul, Republic of Korea
- Center of Cell- and Bio-Therapy (CBT), Seoul National University Hospital, Seoul, Republic of Korea
| | - Cheong-Whan Chae
- National Research Laboratory for Stem Cell Niche, Center for Medical Innovation, Seoul National University Hospital, Seoul, Republic of Korea
- Center of Cell- and Bio-Therapy (CBT), Seoul National University Hospital, Seoul, Republic of Korea
| | - Jae-Il Choi
- National Research Laboratory for Stem Cell Niche, Center for Medical Innovation, Seoul National University Hospital, Seoul, Republic of Korea
- Center of Cell- and Bio-Therapy (CBT), Seoul National University Hospital, Seoul, Republic of Korea
| | - Injoo Hwang
- National Research Laboratory for Stem Cell Niche, Center for Medical Innovation, Seoul National University Hospital, Seoul, Republic of Korea
- Center of Cell- and Bio-Therapy (CBT), Seoul National University Hospital, Seoul, Republic of Korea
| | - Ji-Yeon Yun
- National Research Laboratory for Stem Cell Niche, Center for Medical Innovation, Seoul National University Hospital, Seoul, Republic of Korea
- Center of Cell- and Bio-Therapy (CBT), Seoul National University Hospital, Seoul, Republic of Korea
| | - Jin-A Kang
- National Research Laboratory for Stem Cell Niche, Center for Medical Innovation, Seoul National University Hospital, Seoul, Republic of Korea
- Center of Cell- and Bio-Therapy (CBT), Seoul National University Hospital, Seoul, Republic of Korea
| | - Young-Eun Choi
- National Research Laboratory for Stem Cell Niche, Center for Medical Innovation, Seoul National University Hospital, Seoul, Republic of Korea
- Center of Cell- and Bio-Therapy (CBT), Seoul National University Hospital, Seoul, Republic of Korea
| | - Young Hyun Kim
- National Research Laboratory for Stem Cell Niche, Center for Medical Innovation, Seoul National University Hospital, Seoul, Republic of Korea
- Center of Cell- and Bio-Therapy (CBT), Seoul National University Hospital, Seoul, Republic of Korea
- Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, and College of Medicine or College of Pharmacy, Seoul National University, Seoul, Republic of Korea
| | - Sang Eun Lee
- National Research Laboratory for Stem Cell Niche, Center for Medical Innovation, Seoul National University Hospital, Seoul, Republic of Korea
- Center of Cell- and Bio-Therapy (CBT), Seoul National University Hospital, Seoul, Republic of Korea
| | - Cheol Lee
- Department of Pathology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Dong Hyun Jo
- Department of Anatomy, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Heeyoung Seok
- Genomics Core Facility, Department of Transdisciplinary Research and Collaboration, Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
| | - Byong Seung Cho
- ExoCoBio Inc, Gasan digital 1-ro, Geumcheon-gu, Seoul, 08594, Republic of Korea
| | - Sung Hee Baek
- Creative Research Initiative Center for Chromatin Dynamics, School of Biological Sciences, Seoul National University, Seoul, 151-742, Republic of Korea
| | - Hyo-Soo Kim
- National Research Laboratory for Stem Cell Niche, Center for Medical Innovation, Seoul National University Hospital, Seoul, Republic of Korea.
- Center of Cell- and Bio-Therapy (CBT), Seoul National University Hospital, Seoul, Republic of Korea.
- Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, and College of Medicine or College of Pharmacy, Seoul National University, Seoul, Republic of Korea.
- Department of Internal Medicine, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 110-744, Korea.
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Wu Z, Tan R, Zhu L, Yao P, Hu Q. Protein S-Palmitoylation and Lung Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1304:165-186. [PMID: 34019269 DOI: 10.1007/978-3-030-68748-9_10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
S-palmitoylation of protein is a posttranslational, reversible lipid modification; it was catalyzed by a family of 23 mammalian palmitoyl acyltransferases in humans. S-palmitoylation can impact protein function by regulating protein sorting, secretion, trafficking, stability, and protein interaction. Thus, S-palmitoylation plays a crucial role in many human diseases including mental illness and cancers. In this chapter, we systematically reviewed the influence of S-palmitoylation on protein performance, the characteristics of S-palmitoylation regulating protein function, and the role of S-palmitoylation in pulmonary inflammation and pulmonary hypertension and summed up the treatment strategies of S-palmitoylation-related diseases and the research status of targeted S-palmitoylation agonists/inhibitors. In conclusion, we highlighted the potential role of S-palmitoylation and depalmitoylation in the treatment of human diseases.
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Affiliation(s)
- Zeang Wu
- School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,First Affiliated Hospital, School of Medicine, Shihezi University, Shihezi, China.,School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Rubin Tan
- School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,School of Basic Medicine, Xuzhou Medical University, Xuzhou, China
| | - Liping Zhu
- School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ping Yao
- School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Qinghua Hu
- School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
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TULP1 and TUB Are Required for Specific Localization of PRCD to Photoreceptor Outer Segments. Int J Mol Sci 2020; 21:ijms21228677. [PMID: 33213002 PMCID: PMC7698587 DOI: 10.3390/ijms21228677] [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: 10/29/2020] [Revised: 11/11/2020] [Accepted: 11/16/2020] [Indexed: 11/28/2022] Open
Abstract
Photoreceptor disc component (PRCD) is a small protein which is exclusively localized to photoreceptor outer segments, and is involved in the formation of photoreceptor outer segment discs. Mutations in PRCD are associated with retinal degeneration in humans, mice, and dogs. The purpose of this work was to identify PRCD-binding proteins in the retina. PRCD protein-protein interactions were identified when implementing the Ras recruitment system (RRS), a cytoplasmic-based yeast two-hybrid system, on a bovine retina cDNA library. An interaction between PRCD and tubby-like protein 1 (TULP1) was identified. Co-immunoprecipitation in transfected mammalian cells confirmed that PRCD interacts with TULP1, as well as with its homolog, TUB. These interactions were mediated by TULP1 and TUB highly conserved C-terminal tubby domain. PRCD localization was altered in the retinas of TULP1- and TUB-deficient mice. These results show that TULP1 and TUB, which are involved in the vesicular trafficking of several photoreceptor proteins from the inner segment to the outer segment, are also required for PRCD exclusive localization to photoreceptor outer segment discs.
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11
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Sechrest ER, Murphy J, Senapati S, Goldberg AFX, Park PSH, Kolandaivelu S. Loss of PRCD alters number and packaging density of rhodopsin in rod photoreceptor disc membranes. Sci Rep 2020; 10:17885. [PMID: 33087780 PMCID: PMC7577997 DOI: 10.1038/s41598-020-74628-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 09/28/2020] [Indexed: 02/06/2023] Open
Abstract
Progressive rod-cone degeneration (PRCD) is a small protein localized to photoreceptor outer segment (OS) disc membranes. Several mutations in PRCD are linked to retinitis pigmentosa (RP) in canines and humans, and while recent studies have established that PRCD is required for high fidelity disc morphogenesis, its precise role in this process remains a mystery. To better understand the part which PRCD plays in disease progression as well as its contribution to photoreceptor OS disc morphogenesis, we generated a Prcd-KO animal model using CRISPR/Cas9. Loss of PRCD from the retina results in reduced visual function accompanied by slow rod photoreceptor degeneration. We observed a significant decrease in rhodopsin levels in Prcd-KO retina prior to photoreceptor degeneration. Furthermore, ultrastructural analysis demonstrates that rod photoreceptors lacking PRCD display disoriented and dysmorphic OS disc membranes. Strikingly, atomic force microscopy reveals that many disc membranes in Prcd-KO rod photoreceptor neurons are irregular, containing fewer rhodopsin molecules and decreased rhodopsin packing density compared to wild-type discs. This study strongly suggests an important role for PRCD in regulation of rhodopsin incorporation and packaging density into disc membranes, a process which, when dysregulated, likely gives rise to the visual defects observed in patients with PRCD-associated RP.
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Affiliation(s)
- Emily R Sechrest
- Department of Pharmaceutical Sciences, One Medical Center Drive, West Virginia University, Morgantown, WV, 26506-9193, USA.,Department of Ophthalmology and Visual Sciences, Eye Institute, One Medical Center Drive, West Virginia University, Morgantown, WV, 26506-9193, USA
| | - Joseph Murphy
- Department of Ophthalmology and Visual Sciences, Eye Institute, One Medical Center Drive, West Virginia University, Morgantown, WV, 26506-9193, USA.,Department of Biochemistry, One Medical Center Drive, West Virginia University, Morgantown, WV, 26506-9193, USA
| | - Subhadip Senapati
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, 44106, USA
| | | | - Paul S-H Park
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Saravanan Kolandaivelu
- Department of Ophthalmology and Visual Sciences, Eye Institute, One Medical Center Drive, West Virginia University, Morgantown, WV, 26506-9193, USA. .,Department of Biochemistry, One Medical Center Drive, West Virginia University, Morgantown, WV, 26506-9193, USA.
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12
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Spencer WJ, Lewis TR, Pearring JN, Arshavsky VY. Photoreceptor Discs: Built Like Ectosomes. Trends Cell Biol 2020; 30:904-915. [PMID: 32900570 DOI: 10.1016/j.tcb.2020.08.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 08/05/2020] [Accepted: 08/11/2020] [Indexed: 01/22/2023]
Abstract
The light-sensitive outer segment organelle of the vertebrate photoreceptor cell is a modified cilium filled with hundreds of flattened 'disc' membranes that provide vast light-absorbing surfaces. The outer segment is constantly renewed with new discs added at its base every day. This continuous process is essential for photoreceptor viability. In this review, we describe recent breakthroughs in the understanding of disc morphogenesis, with a focus on the molecular mechanisms responsible for initiating disc formation from the ciliary membrane. We highlight the discoveries that this mechanism evolved from an innate ciliary process of releasing small extracellular vesicles, or ectosomes, and that both disc formation and ectosome release rely on the actin cytoskeleton.
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Affiliation(s)
- William J Spencer
- Albert Eye Research Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Tylor R Lewis
- Albert Eye Research Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Jillian N Pearring
- Department of Ophthalmology, University of Michigan, Ann Arbor, MI 48105, USA; Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48105, USA
| | - Vadim Y Arshavsky
- Albert Eye Research Institute, Duke University Medical Center, Durham, NC 27710, USA.
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Shahid M, Kim M, Jin P, Zhou B, Wang Y, Yang W, You S, Kim J. S-Palmitoylation as a Functional Regulator of Proteins Associated with Cisplatin Resistance in Bladder Cancer. Int J Biol Sci 2020; 16:2490-2505. [PMID: 32792852 PMCID: PMC7415425 DOI: 10.7150/ijbs.45640] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 05/02/2020] [Indexed: 12/25/2022] Open
Abstract
Protein S-palmitoylation is a powerful post-translational modification that regulates protein trafficking, localization, turnover, and signal transduction. Palmitoylation controls several important cellular processes, and, if dysregulated, can lead to cancer, cardiovascular disease, and neurological disorders. The role of protein palmitoylation in mediating resistance to systemic cisplatin-based chemotherapies in cancer is currently unknown. This is of particular interest because cisplatin is currently the gold standard of treatment for bladder cancer (BC), and there are no feasible options after resistance is acquired. Using unbiased global proteomic profiling of purified S-palmitoylated peptides combined with intensive bioinformatics analyses, we identified 506 candidate palmitoylated proteins significantly enriched in cisplatin-resistant BC cells. One of these proteins included PD-L1, which is highly palmitoylated in resistant cells. Pharmacological inhibition of fatty acid synthase (FASN) suppressed PD-L1 palmitoylation and expression, which suggests the potential use of FASN-PD-L1-targeted therapeutic strategies in BC patients. Taken together, these results highlight the role of protein palmitoylation in mediating BC chemoresistance.
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Affiliation(s)
- Muhammad Shahid
- Departments of Surgery and Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Minhyung Kim
- Departments of Surgery and Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Peng Jin
- Departments of Surgery and Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Bo Zhou
- Departments of Surgery and Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Yang Wang
- Departments of Surgery and Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Wei Yang
- Departments of Surgery and Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, USA.,Department of Medicine, University of California Los Angeles, CA 90095, USA
| | - Sungyong You
- Departments of Surgery and Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Jayoung Kim
- Departments of Surgery and Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, USA.,Department of Medicine, University of California Los Angeles, CA 90095, USA
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14
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Stix R, Lee CJ, Faraldo-Gómez JD, Banerjee A. Structure and Mechanism of DHHC Protein Acyltransferases. J Mol Biol 2020; 432:4983-4998. [PMID: 32522557 DOI: 10.1016/j.jmb.2020.05.023] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 05/26/2020] [Accepted: 05/28/2020] [Indexed: 01/01/2023]
Abstract
S-acylation, whereby a fatty acid chain is covalently linked to a cysteine residue by a thioester linkage, is the most prevalent kind of lipid modification of proteins. Thousands of proteins are targets of this post-translational modification, which is catalyzed by a family of eukaryotic integral membrane enzymes known as DHHC protein acyltransferases (DHHC-PATs). Our knowledge of the repertoire of S-acylated proteins has been rapidly expanding owing to development of the chemoproteomic techniques. There has also been an increasing number of reports in the literature documenting the importance of S-acylation in human physiology and disease. Recently, the first atomic structures of two different DHHC-PATs were determined using X-ray crystallography. This review will focus on the insights gained into the molecular mechanism of DHHC-PATs from these structures and highlight representative data from the biochemical literature that they help explain.
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Affiliation(s)
- Robyn Stix
- Theoretical Molecular Biophysics Laboratory, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Chul-Jin Lee
- Unit on Structural and Chemical Biology of Membrane Proteins, Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - José D Faraldo-Gómez
- Theoretical Molecular Biophysics Laboratory, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Anirban Banerjee
- Unit on Structural and Chemical Biology of Membrane Proteins, Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
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15
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Spencer WJ, Ding JD, Lewis TR, Yu C, Phan S, Pearring JN, Kim KY, Thor A, Mathew R, Kalnitsky J, Hao Y, Travis AM, Biswas SK, Lo WK, Besharse JC, Ellisman MH, Saban DR, Burns ME, Arshavsky VY. PRCD is essential for high-fidelity photoreceptor disc formation. Proc Natl Acad Sci U S A 2019; 116:13087-13096. [PMID: 31189593 PMCID: PMC6601265 DOI: 10.1073/pnas.1906421116] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Progressive rod-cone degeneration (PRCD) is a small protein residing in the light-sensitive disc membranes of the photoreceptor outer segment. Until now, the function of PRCD has remained enigmatic despite multiple demonstrations that its mutations cause blindness in humans and dogs. Here, we generated a PRCD knockout mouse and observed a striking defect in disc morphogenesis, whereby newly forming discs do not properly flatten. This leads to the budding of disc-derived vesicles, specifically at the site of disc morphogenesis, which accumulate in the interphotoreceptor matrix. The defect in nascent disc flattening only minimally alters the photoreceptor outer segment architecture beyond the site of new disc formation and does not affect the abundance of outer segment proteins and the photoreceptor's ability to generate responses to light. Interestingly, the retinal pigment epithelium, responsible for normal phagocytosis of shed outer segment material, lacks the capacity to clear the disc-derived vesicles. This deficiency is partially compensated by a unique pattern of microglial migration to the site of disc formation where they actively phagocytize vesicles. However, the microglial response is insufficient to prevent vesicular accumulation and photoreceptors of PRCD knockout mice undergo slow, progressive degeneration. Taken together, these data show that the function of PRCD is to keep evaginating membranes of new discs tightly apposed to each other, which is essential for the high fidelity of photoreceptor disc morphogenesis and photoreceptor survival.
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Affiliation(s)
- William J Spencer
- Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710
| | - Jin-Dong Ding
- Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710
| | - Tylor R Lewis
- Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710
| | - Chen Yu
- Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710
| | - Sebastien Phan
- National Center for Microscopy and Imaging Research, School of Medicine, University of California San Diego, La Jolla, CA 92093
| | - Jillian N Pearring
- Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710
| | - Keun-Young Kim
- National Center for Microscopy and Imaging Research, School of Medicine, University of California San Diego, La Jolla, CA 92093
| | - Andrea Thor
- National Center for Microscopy and Imaging Research, School of Medicine, University of California San Diego, La Jolla, CA 92093
| | - Rose Mathew
- Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710
| | - Joan Kalnitsky
- Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710
| | - Ying Hao
- Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710
| | - Amanda M Travis
- Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710
| | - Sondip K Biswas
- Department of Neurobiology, Morehouse School of Medicine, Atlanta, GA 30310
| | - Woo-Kuen Lo
- Department of Neurobiology, Morehouse School of Medicine, Atlanta, GA 30310
| | - Joseph C Besharse
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, WI 53226
| | - Mark H Ellisman
- National Center for Microscopy and Imaging Research, School of Medicine, University of California San Diego, La Jolla, CA 92093
| | - Daniel R Saban
- Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710
| | - Marie E Burns
- Department of Cell Biology and Human Anatomy, University of California, Davis, CA 95616
- Department of Ophthalmology, University of California, Davis, CA 95616
| | - Vadim Y Arshavsky
- Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710;
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710
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Strassburger K, Kang E, Teleman AA. Drosophila ZDHHC8 palmitoylates scribble and Ras64B and controls growth and viability. PLoS One 2019; 14:e0198149. [PMID: 30735487 PMCID: PMC6368284 DOI: 10.1371/journal.pone.0198149] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 01/24/2019] [Indexed: 12/20/2022] Open
Abstract
Palmitoylation is an important posttranslational modification regulating diverse cellular functions. Consequently, aberrant palmitoylation can lead to diseases such as neuronal disorders or cancer. In humans there are roughly one hundred times more palmitoylated proteins than enzymes catalyzing palmitoylation (palmitoyltransferases). Therefore, it is an important challenge to establish the links between palmitoyltransferases and their targets. From publicly available data, we find that expression of human ZDHHC8 correlates significantly with cancer survival. To elucidate the organismal function of ZDHHC8, we study the Drosophila ortholog of hZDHHC8, CG34449/dZDHHC8. Knockdown of dZDHHC8 causes tissue overgrowth while dZDHHC8 mutants are larval lethal. We provide a list of 159 palmitoylated proteins in Drosophila and present data suggesting that scribble and Ras64B are targets of dZDHHC8.
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Affiliation(s)
- Katrin Strassburger
- German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg University, Heidelberg, Germany
| | - Evangeline Kang
- German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg University, Heidelberg, Germany
| | - Aurelio A. Teleman
- German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg University, Heidelberg, Germany
- * E-mail:
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PRCD Is a Small Disc-Specific Rhodopsin-Binding Protein of Unknown Function. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1185:531-535. [PMID: 31884666 DOI: 10.1007/978-3-030-27378-1_87] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
PRCD (progressive rod-cone degeneration) is a small ~6 kDa protein with unknown function that specifically resides in photoreceptor discs and interacts with rhodopsin. PRCD's discovery resulted from decades-long study of a canine retinal disease called progressive rod-cone degeneration which is one of the most frequent causes of blindness in dogs characterized by the slow, progressive death of rod photoreceptors followed by cones. A series of genetic studies eventually mapped the disease to a single point mutation in a novel gene which was then named Prcd. Highlighting the importance of this gene, this and several other mutations have been identified in human patients suffering from retinitis pigmentosa. In this review, we highlight what is currently known about PRCD protein, including the etiology and pathology of the retinal disease caused by its mutation, the protein's trafficking, localization, and biochemical characterization.
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18
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The molecular mechanism of DHHC protein acyltransferases. Biochem Soc Trans 2018; 47:157-167. [PMID: 30559274 DOI: 10.1042/bst20180429] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 11/01/2018] [Accepted: 11/06/2018] [Indexed: 01/04/2023]
Abstract
Protein S-acylation is a reversible lipidic posttranslational modification where a fatty acid chain is covalently linked to cysteine residues by a thioester linkage. A family of integral membrane enzymes known as DHHC protein acyltransferases (DHHC-PATs) catalyze this reaction. With the rapid development of the techniques used for identifying lipidated proteins, the repertoire of S-acylated proteins continues to increase. This, in turn, highlights the important roles that S-acylation plays in human physiology and disease. Recently, the first molecular structures of DHHC-PATs were determined using X-ray crystallography. This review will comment on the insights gained on the molecular mechanism of S-acylation from these structures in combination with a wealth of biochemical data generated by researchers in the field.
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De I, Sadhukhan S. Emerging Roles of DHHC-mediated Protein S-palmitoylation in Physiological and Pathophysiological Context. Eur J Cell Biol 2018; 97:319-338. [DOI: 10.1016/j.ejcb.2018.03.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 03/14/2018] [Accepted: 03/16/2018] [Indexed: 02/08/2023] Open
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20
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Jiang H, Zhang X, Chen X, Aramsangtienchai P, Tong Z, Lin H. Protein Lipidation: Occurrence, Mechanisms, Biological Functions, and Enabling Technologies. Chem Rev 2018; 118:919-988. [PMID: 29292991 DOI: 10.1021/acs.chemrev.6b00750] [Citation(s) in RCA: 286] [Impact Index Per Article: 47.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Protein lipidation, including cysteine prenylation, N-terminal glycine myristoylation, cysteine palmitoylation, and serine and lysine fatty acylation, occurs in many proteins in eukaryotic cells and regulates numerous biological pathways, such as membrane trafficking, protein secretion, signal transduction, and apoptosis. We provide a comprehensive review of protein lipidation, including descriptions of proteins known to be modified and the functions of the modifications, the enzymes that control them, and the tools and technologies developed to study them. We also highlight key questions about protein lipidation that remain to be answered, the challenges associated with answering such questions, and possible solutions to overcome these challenges.
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Affiliation(s)
- Hong Jiang
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Xiaoyu Zhang
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Xiao Chen
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Pornpun Aramsangtienchai
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Zhen Tong
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Hening Lin
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
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