Sarkar Bonoshree, Mondal Muhammad Safiul Alam, Rahman Taibur, Hosen Md Ismail, Rahman Atiqur
Infection Biology Laboratory, Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, Bangladesh.
Clinical Biochemistry and Translational Medicine Laboratory, Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, Bangladesh.
PLoS One. 2024 Dec 23;19(12):e0312733. doi: 10.1371/journal.pone.0312733. eCollection 2024.
CXCR4, a chemokine receptor known as Fusin or CD184, spans the outer membrane of various human cells, including leukocytes. This receptor is essential for HIV infection as well as for many vital cellular processes and is implicated to be associated with multiple pathologies, including cancers. This study employs various computational tools to investigate the molecular effects of disease-vulnerable germ-line missense and non-coding SNPs of the CXCR4 gene. In this investigation, the tools SIFT, PROVEAN, PolyPhen-2, PANTHER, SNAP 2.0, PhD-SNP, and SNPs&GO were used to predict potentially harmful and disease-causing nsSNPs in CXCR4. Additionally, their impact on protein stability was examined by I-mutant 3.0, MUpro, Consurf, and Netsurf 2.0, combined with conservation and solvent accessibility analyses. Structural analysis with normal and mutant residues of the protein harboring these disease-associated functional SNPs was conducted using TM-align and SWIS MODEL, with visualization aided by PyMOL and the BIOVINA Discovery Studio Visualizer. The functional impact of wild-type and mutated CXCR4 variants was evaluated through molecular docking with its natural ligand CXCR4-modulator 1, using the PyRx tool. Non-coding SNPs in the 3' -UTR were investigated for their regulatory effects on miRNA binding sites using PolymiRTS. Five non-coding SNPs were identified in the 3'-UTR that can disrupt existing miRNA binding sites or create new ones. Non-coding SNPs in the 5' and 3'-UTRs, as well as in intronic regions, were also examined for their potential roles in gene expression regulation. Furthermore, RegulomeDB databases were employed to assess the regulatory potential of these non-coding SNPs based on chromatin state and protein binding regulation. In the mostly annotated variant (ENSP00000241393) of the CXCR4 gene, we found 23 highly deleterious and pathogenic nsSNPs and these were selected for in-depth analysis. Among the 23 nsSNPs, five (G55V, H79P, L80P, H113P, and P299L) displayed notable structural alternation, with elevated RMSD values and reduced TM (TM-score) values. A molecular docking study revealed the significant impact of the H113P variant on the protein-ligand binding affinity, supported by MD simulation over 100 nanoseconds, which highlighted substantial stability differences between wild-type and H113P mutated proteins during ligand binding. This comprehensive analysis shed light on the potential functional consequences of genetic variation in the CXCR genes, offering valuable insights into the implications of disease susceptibility and may pave the way for future therapeutic interventions.
CXCR4是一种被称为Fusin或CD184的趋化因子受体,跨越包括白细胞在内的各种人类细胞的外膜。该受体对于HIV感染以及许多重要的细胞过程至关重要,并且被认为与多种病理状况有关,包括癌症。本研究采用各种计算工具来研究CXCR4基因疾病易感性种系错义突变和非编码单核苷酸多态性(SNP)的分子效应。在这项研究中,使用SIFT、PROVEAN、PolyPhen-2、PANTHER、SNAP 2.0、PhD-SNP和SNPs&GO等工具来预测CXCR4中潜在有害和致病的非同义单核苷酸多态性(nsSNP)。此外,通过I-mutant 3.0、MUpro、Consurf和Netsurf 2.0结合保守性和溶剂可及性分析,研究了它们对蛋白质稳定性的影响。使用TM-align和SWIS MODEL对携带这些与疾病相关的功能性SNP的蛋白质的正常和突变残基进行结构分析,并借助PyMOL和BIOVINA Discovery Studio Visualizer进行可视化。使用PyRx工具通过与天然配体CXCR4调节剂1进行分子对接,评估野生型和突变型CXCR4变体的功能影响。使用PolymiRTS研究3'-非翻译区(UTR)中的非编码SNP对miRNA结合位点的调控作用。在3'-UTR中鉴定出五个非编码SNP,它们可以破坏现有的miRNA结合位点或产生新的结合位点。还研究了5'和3'-UTR以及内含子区域中的非编码SNP在基因表达调控中的潜在作用。此外,使用RegulomeDB数据库基于染色质状态和蛋白质结合调控来评估这些非编码SNP的调控潜力。在CXCR4基因的大多数注释变体(ENSP00000241393)中,我们发现了23个高度有害和致病的nsSNP,并选择这些进行深入分析。在这23个nsSNP中,五个(G55V、H79P、L80P、H113P和P299L)表现出明显的结构变化,均方根偏差(RMSD)值升高,TM(TM分数)值降低。分子对接研究揭示了H113P变体对蛋白质-配体结合亲和力的显著影响,超过100纳秒的分子动力学(MD)模拟支持了这一点,该模拟突出了野生型和H113P突变型蛋白质在配体结合过程中的显著稳定性差异。这种全面分析揭示了CXCR基因遗传变异的潜在功能后果,为疾病易感性的影响提供了有价值的见解,并可能为未来的治疗干预铺平道路。