Integrative In Silico Characterization of Klotho Missense Variants rs9527025 and rs9536314: Structural Perturbation Prediction, Tissue Expression, and Functional Network Analysis

Authors

DOI:

https://doi.org/10.12928/jbns.v6i1.16188

Keywords:

Klotho, KL-VS, SNP, Protein structure, In silico analysis

Abstract

The Klotho (KL) gene encodes a transmembrane protein that serves as an obligate co-receptor for fibroblast growth factor 23 (FGF23), regulating phosphate homeostasis, vitamin D metabolism, and aging-related signaling. The KL-VS haplotype carries two coding variants, rs9536314 (Phe352Val) and rs9527025 (Cys370Ser), with established contrasting functional effects: F352V impairs secretion through intracellular retention, while C370S enhances secretion. The structural basis of these opposing phenotypes remains uncharacterized, and non-KL-VS substitutions at position 370 from the multiallelic rs9527025 have not been computationally evaluated. This study presents an integrative in silico characterization of rs9527025 and rs9536314 in the KL1 domain of α-Klotho, combining multi-algorithm functional prediction, predicted thermodynamic perturbation analysis, tissue-specific expression profiling, and gene interaction network analysis. Results showed that rs9536314 substitutions consistently predicted greater functional damage and thermodynamic perturbation (ΔΔG up to -3.02 kcal/mol for F352V), consistent with disruption of the KL1 hydrophobic core as a structural basis for its secretion-impairing phenotype. For rs9527025, C370S (the KL-VS substitution) showed minimal predicted perturbation in line with its secretion-enhancing effect, while the uncharacterized C370Y and C370F substitutions showed inconsistent predictions suggesting more localized effects. GTEx analysis confirmed predominant KL expression in kidney cortex, contextualizing variant relevance in renal mineral metabolism. Network analysis identified KL as a central hub in the FGF23-FGFR signaling axis. These computational findings offer a structural interpretation that bridges predicted perturbations at residues 352 and 370 with their known contrasting functional effects on Klotho processing and secretion.

References

Arking, D. E., Krebsova, A., Macek, M., Sr., Macek, M., Jr., Arking, A., Mian, I. S., Fried, L., Hamosh, A., Dey, S., McIntosh, I., & Dietz, H. C. (2002). Association of human aging with a functional variant of klotho. Proceedings of the National Academy of Sciences of the United States of America, 99(2), 856-861. https://doi.org/10.1073/pnas.022484299

Betz, S. F. (1993). Disulfide bonds and the stability of globular proteins. Protein Science, 2(10), 1551-1558. https://doi.org/10.1002/pro.5560021002

Lee, J., Ju, K. D., Kim, H. J., Tsogbadrakh, B., Ryu, H., Kang, E., Kang, M., Yang, J., Kang, H. G., Ahn, C., & Oh, K. H. (2021). Soluble α-Klotho anchors TRPV5 to the distal tubular cell membrane independent of FGFR1 by binding TRPV5 and galectin-1 simultaneously. American Journal of Physiology-Renal Physiology, 320(4), F559-F568. https://doi.org/10.1152/ajprenal.00044.2021

Dalton, G. D., Xie, J., An, S. W., & Huang, C. L. (2021). New insights into the mechanism of action of soluble klotho. Frontiers in Endocrinology, 8, 323. https://doi.org/10.3389/fendo.2017.00323

Citterio, L., Delli Carpini, S., Lupoli, S., Brioni, E., Simonini, M., Fontana, S., Zagato, L., Messaggio, E., Barlassina, C., Cusi, D., Manunta, P., & Lanzani, C. (2020). Klotho gene in human salt-sensitive hypertension. Clinical Journal of the American Society of Nephrology, 15(3), 375-383. https://doi.org/10.2215/CJN.08620719

Doi, S., Zou, Y., Togao, O., Pastor, J. V., John, G. B., Wang, L., Shiizaki, K., Gotschall, R., Schiavi, S., Yorioka, N., Takahashi, M., Boothman, D. A., & Kuro-O, M. (2011). Klotho inhibits transforming growth factor-beta1 (TGF-beta1) signaling and suppresses renal fibrosis and cancer metastasis in mice. Journal of Biological Chemistry, 286(10), 8655-8665. https://doi.org/10.1074/jbc.M110.174037

Hu, M. C., Shi, M., Zhang, J., Quinones, H., Griffith, C., Kuro-o, M., & Moe, O. W. (2011). Klotho deficiency causes vascular calcification in chronic kidney disease. Journal of the American Society of Nephrology, 22(1), 124-136. https://doi.org/10.1681/ASN.2009121311

Kuro-o, M. (2019). The Klotho proteins in health and disease. Nature Reviews Nephrology, 15, 27-44. https://doi.org/10.1038/s41581-018-0078-3

Kuro-o, M., Matsumura, Y., Aizawa, H., Kawaguchi, H., Suga, T., Utsugi, T., Ohyama, Y., Kurabayashi, M., Kaname, T., Kume, E., Iwasaki, H., Iida, A., Shiraki-Iida, T., Nishikawa, S., Nagai, R., & Nabeshima, Y. (1997). Mutation of the mouse klotho gene leads to a syndrome resembling ageing. Nature, 390, 45-51. https://doi.org/10.1038/36285

Ortega, M. A., Boaru, D. L., De Leon-Oliva, D., De Castro-Martinez, P., Minaya-Bravo, A. M., Casanova-Martin, C., Barrena-Blazquez, S., Garcia-Montero, C., Fraile-Martinez, O., Lopez-Gonzalez, L., Saez, M. A., Alvarez-Mon, M., & Diaz-Pedrero, R. (2025). The impact of Klotho in cancer: From development and progression to therapeutic potential. Genes, 16(2), 128. https://doi.org/10.3390/genes16020128

Tang, X., Wang, Y., Fan, Z., Ji, G., Wang, M., Lin, J., Huang, S., & Meltzer, S. J. (2016). Klotho: A tumor suppressor and modulator of the Wnt/beta-catenin pathway in human hepatocellular carcinoma. Laboratory Investigation, 96(2), 197-205. https://doi.org/10.1038/labinvest.2015.86

Tokuriki, N., & Tawfik, D. S. (2009). Stability effects of mutations and protein evolvability. Current Opinion in Structural Biology, 19, 596-604. https://doi.org/10.1016/j.sbi.2009.08.003

Wolf, M. T., An, S. W., Nie, M., Bal, M. S., & Huang, C. L. (2014). Klotho up-regulates renal calcium channel transient receptor potential vanilloid 5 (TRPV5) by intra- and extracellular N-glycosylation-dependent mechanisms. Journal of Biological Chemistry, 289(52), 35849-35857. https://doi.org/10.1074/jbc.M114.616649

Wu, P. H., Westerberg, P. A., Kindmark, A., Tivesten, A., Karlsson, M. K., Mellstrom, D., Ohlsson, C., Fellstrom, B., Linde, T., & Ljunggren, O. (2020). The association between single nucleotide polymorphisms of Klotho gene and mortality in elderly men: The MrOS Sweden study. Scientific Reports, 10, 10243. https://doi.org/10.1038/s41598-020-66517-5

Ligumsky, H., Merenbakh-Lamin, K., Keren-Khadmy, N., Wolf, I., & Rubinek, T. (2022). The role of α-klotho in human cancer: molecular and clinical aspects. Oncogene, 41(40), 4487–4497. https://doi.org/10.1038/s41388-022-02440-5

Xu, Y., & Sun, Z. (2015). Molecular basis of Klotho: From gene to function in aging. Endocrine Reviews, 36(2), 174-193. https://doi.org/10.1210/er.2013-1079

Zhu, Z., Xia, W., Cui, Y., Zhen, J., Hao, Y., Yin, S., Wang, D., Meng, S., & Han, S. (2019). Klotho gene polymorphisms are associated with healthy aging and longevity: Evidence from a meta-analysis. Mechanisms of Ageing and Development, 178, 33-40. https://doi.org/10.1016/j.mad.2018.12.003

Zsemlye, E., Durmanova, V., Kluckova, K., Svajdler, M., Cierny, D., Lehotsky, J., & Hajduchova, H. (2025). Association of Klotho gene polymorphism and serum level of alpha Klotho protein with different tumor grades, overall survival and cytokine profile in glioma patients. International Journal of Molecular Sciences, 26(1), 330. https://doi.org/10.3390/ijms26010330

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2026-06-30

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