UNVEILING THE EFFECT OF PHOSPHORYLATION AND PH CONDITIONS ON THE CONFORMATIONAL DYNAMICS TMEM176B WITH A APPROACH BASED ON HYBRID METHODS

TMEM176 proteins consist of an ion channel expressed in immune cells and certain types of cancer. This protein may play the role of oncogenes, tumor suppressor and biological marker. Marcelo Hill (Pasteur Institute - Montevideo) showed that the TMEM176B expression is inversely correlated with inflammasome activation in critical patients with Covid-19. The number of works about its functionality with in silico experiments is expressive. However, almost nothing is known about its structure and conformational dynamics. We are applying a protocol to understand better the relationship between its function and its conformational dynamic. This work presents an initial study about the effect of two phosphorylations and three pH conditions on the Wild Type and on two mutants (A134T and F203A) structures. We used an Alphafold model available on the Uniprot and investigated a total of 12 systems. Following, we performed the Normal Modes Analysis, selected the modes and applied the hybrid method VMOD to sampling the conformational space. In the next step, we found the most closed and opened conformations for each system. In the last step, we analyzed the Principal Components and we projected population distributions onto subspace spanned by PC1 and PC2 for generated ensembles using Prody. Although the phosphorylations and mutations are localized far from the channel entrance, they have a significant effect on the closure and opening mechanisms and may affect the transmembrane functionality.