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Da Silva E, Scott MGH, Enslen H, Marullo S. Control of CCR5 Cell-Surface Targeting by the PRAF2 Gatekeeper. Int J Mol Sci 2023; 24:17438. [PMID: 38139265 PMCID: PMC10744302 DOI: 10.3390/ijms242417438] [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: 11/09/2023] [Revised: 12/08/2023] [Accepted: 12/09/2023] [Indexed: 12/24/2023] Open
Abstract
The cell-surface targeting of neo-synthesized G protein-coupled receptors (GPCRs) involves the recruitment of receptors into COPII vesicles budding at endoplasmic reticulum exit sites (ERESs). This process is regulated for some GPCRs by escort proteins, which facilitate their export, or by gatekeepers that retain the receptors in the ER. PRAF2, an ER-resident four trans- membrane domain protein with cytoplasmic extremities, operates as a gatekeeper for the GB1 protomer of the heterodimeric GABAB receptor, interacting with a tandem di-leucine/RXR retention motif in the carboxyterminal tail of GB1. PRAF2 was also reported to interact in a two-hybrid screen with a peptide corresponding to the carboxyterminal tail of the chemokine receptor CCR5 despite the absence of RXR motifs in its sequence. Using a bioluminescence resonance energy transfer (BRET)-based subcellular localization system, we found that PRAF2 inhibits, in a concentration-dependent manner, the plasma membrane export of CCR5. BRET-based proximity assays and Co-IP experiments demonstrated that PRAF2/CCR5 interaction does not require the presence of a receptor carboxyterminal tail and involves instead the transmembrane domains of both proteins. The mutation of the potential di-leucine/RXR motif contained in the third intracellular loop of CCR5 does not affect PRAF2-mediated retention. It instead impairs the cell-surface export of CCR5 by inhibiting CCR5's interaction with its private escort protein, CD4. PRAF2 and CD4 thus display opposite roles on the cell-surface export of CCR5, with PRAF2 inhibiting and CD4 promoting this process, likely operating at the level of CCR5 recruitment into COPII vesicles, which leave the ER.
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Affiliation(s)
| | | | | | - Stefano Marullo
- CNRS, INSERM, Institut Cochin, Université Paris Cité, F-75014 Paris, France; (E.D.S.); (M.G.H.S.); (H.E.)
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Qian Z, Wei B, Zhou Y, Wang Q, Wang J, Sun Y, Gao Y, Chen X. PRAF2 overexpression predicts poor prognosis and promotes tumorigenesis in esophageal squamous cell carcinoma. BMC Cancer 2019; 19:585. [PMID: 31200670 PMCID: PMC6570937 DOI: 10.1186/s12885-019-5818-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Accepted: 06/11/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Prenylated Rab acceptor 1 domain family, member 2 (PRAF2) is involved in the occurrence and progression of several malignant tumors. However, its potential role in esophageal squamous cell carcinoma (ESCC) is still unknown. METHODS PRAF2 mRNA expression was determined in 77 frozen ESCC samples by quantitative reverse transcription-polymerase chain reaction (qPCR) and its association with clinical features and overall survival were evaluated. The roles of PRAF2 in ESCC cells were investigated by proliferation, cell cycle, invasion and apoptosis assays in vitro. RESULTS The PRAF2 mRNA expression was significantly increased in ESCC tissues compared with matched surrounding non-tumor tissues. Survival analysis showed that high PRAF2 mRNA expression was associated with worse overall survival in ESCC patients. Multivariate analysis revealed that PRAF2 (hazard ratio 2.05, 95% CI 1.10-3.85, P = 0.025) emerged as the independent predictor for poor overall survival in ESCC. The in vitro experiments revealed that knockdown of PRAF2 expression blocked cell proliferation, cell cycle progression and cell invasion and induced cell apoptosis in ESCC cells. CONCLUSION Taken together, our data demonstrate that PRAF2 could be used as a potential prognostic biomarker and represent a potential therapeutic target for ESCC.
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Affiliation(s)
- Zhaoye Qian
- Department of Medical Oncology, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huai'an, 223300, China
| | - Bin Wei
- Department of Medical Oncology, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huai'an, 223300, China
| | - Yu Zhou
- Department of Medical Oncology, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huai'an, 223300, China
| | - Qiuzi Wang
- Department of Medical Oncology, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huai'an, 223300, China
| | - Jiru Wang
- Department of Medical Oncology, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huai'an, 223300, China
| | - Yuan Sun
- Department of Medical Oncology, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huai'an, 223300, China
| | - Yong Gao
- Department of Medical Oncology, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huai'an, 223300, China.
| | - Xiaofei Chen
- Department of Medical Oncology, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huai'an, 223300, China.
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Wang CH, Liu LL, Liao DZ, Zhang MF, Fu J, Lu SX, Chen SL, Wang H, Cai SH, Zhang CZ, Zhang HZ, Yun JP. PRAF2 expression indicates unfavorable clinical outcome in hepatocellular carcinoma. Cancer Manag Res 2018; 10:2241-2248. [PMID: 30100755 PMCID: PMC6065608 DOI: 10.2147/cmar.s166789] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Introduction Prenylated Rab acceptor 1 domain family member 2 (PRAF2), a novel oncogene, has been shown to be essential for the development of several human cancers; however, its role in hepatocellular carcinoma (HCC) remains unclear. Materials and methods PRAF2 mRNA and protein expressions were examined in fresh tissues by quantitative reverse transcription-polymerase chain reaction and Western blot, respectively, and in 518 paraffin-embedded HCC samples by immunohistochemistry. The correlation of PRAF2 expression and clinical outcomes was determined by the Student's t-test, Kaplan-Meier test, and multivariate Cox regression analysis. The role of PRAF2 in HCC was investigated by cell viability, colony formation, and migration assays in vitro and with a nude mouse model in vivo. Results In our study, the PRAF2 expression was noticeably increased in HCC tissues at both the mRNA and protein levels compared with that of the nontumorous tissues. Kaplan-Meier analysis indicated that high PRAF2 expression was correlated with worse overall survival in a cohort of 518 patients with HCC. The prognostic implication of PRAF2 was verified by stratified survival analysis. The multivariate Cox regression model revealed PRAF2 as an independent poor prognostic factor for overall survival (hazard ratio = 1.244, 95% CI: 1.039-1.498, P<0.017) in HCC. The in vitro data demonstrated that PRAF2 overexpression markedly enhanced cell viability, colony formation, and cell migration. Moreover, ectopic expression of PRAF2 promoted tumor growth and metastasis in vivo. Conclusion Collectively, we conclude that PRAF2 is increased in HCC and is a novel unfavorable biomarker for prognostic prediction for patients with HCC.
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Affiliation(s)
- Chun-Hua Wang
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China, ; .,Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou 510060, China, ;
| | - Li-Li Liu
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China, ; .,Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou 510060, China, ;
| | - Ding-Zhun Liao
- Department of Pathology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China
| | - Mei-Fang Zhang
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China, ; .,Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou 510060, China, ;
| | - Jia Fu
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China, ; .,Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou 510060, China, ;
| | - Shi-Xun Lu
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China, ; .,Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou 510060, China, ;
| | - Shi-Lu Chen
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China, ; .,Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou 510060, China, ;
| | - Hong Wang
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China, ; .,Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou 510060, China, ;
| | - Shao-Hang Cai
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China, ; .,Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou 510060, China, ;
| | - Chris Zhiyi Zhang
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China, ; .,Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou 510060, China, ;
| | - Hui-Zhong Zhang
- Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou 510060, China, ;
| | - Jing-Ping Yun
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China, ; .,Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou 510060, China, ;
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