Deleterious effects of non-synonymous single nucleotide variants of human IL-1β gene.

The IL-1β gene is currently topic of interest for its important role in the pathogenesis of intervertebral disk degeneration. The new sequencing technology makes it crucial to study the effects of variants in IL-1β. Thus, 714 IL-1β variants with evidence supporting were collected from the EMBL database. Among them, 62 were non-synonymous single nucleotide variants (nsSNVs). Furthermore, six common nsSNVs were predicted to have damaging effects by SIFT, PolyPhen, PROVEAN and SNPs&GO. Based on the constructed three-dimensional structure of pro-IL-1β, rs375479974 with a mutation of Phe to Ser was proposed to reduce the stability of the pro-IL-1β protein. The rs375479974 variant was found to cause least common stabilizing amino acid residues, decrease hydrophilic and increase hydrophobic surface areas in the greatest degree, and have the lowest free energy alterations in I-Mutant 2.0 sequence analysis. When analyzing the interaction between the experimental 3D structure of mature IL-1β and its neutralizing McAb canakinumab complex, the rs775174784 substitution of Leu with Phe was found to attenuate this interaction by reducing binding energy, while rs375479974 not. Molecular dynamics simulation results in intervertebral disk environment supported rs775174784's effects. These results suggest that both rs375479974 and rs775174784 may have potential clinical and drug target implications.