PhD Scientific Days 2022

Molecular Sciences III. (Poster discussion will take place on the terrace of the room during the Coffee Break)

Investigation of the molecular evolution of CFTR through two key orthologues

Előadó neve

Simon, Márton, MSc

Előadó munkahelye

Department of Biochemistry

Előadó telefonszáma

+36304224806

Előadó e-mail címe

simon.marton@med.semmelweis-univ.hu

Az előadás címe

Investigation of the molecular evolution of CFTR through two key orthologues

Szerző(k) neve és munkahelye

Márton A. Simon, László Csanády
Department of Biochemistry, Semmelweis University, Budapest

Bemutatás módja

Poszter

Szekció

Molecular Sciences III. (Poster discussion will take place on the terrace of the room during the Coffee Break)

Language of the presentation

English

Preferred session

Molecular Sciences

Összefoglaló szövege

CFTR chloride channel mutations can cause cystic fibrosis (CF) a lethal and incurable disease. Phosphorylated CFTR exhibits ‘bursting’ pore gating – ‘bursts’ of openings separated by short ‘flickery’ closures are flanked by long ‘interburst’ closures – driven by ATP binding/hydrolysis at the two nucleotide-binding domains. The zebrafish (zCFTR) and human (hCFTR) orthologues, representing roughly the two ends of CFTR molecular evolution, possess different gating properties in line with structural differences revealed in cryo-EM studies. The R117 side chain, conserved across evolution, forms a crucial H-bond in outward-facing (‘open’) hCFTR which stabilizes the open state, lack of this bond in the R117H mutant causes CF. In the outward-facing zCFTR structure this H-bond cannot be observed, and we found that introducing the R117H mutation into zCFTR has no functional effect. Instead, we discovered a H-bond between the N120 and S109 side chains of outward-facing zCFTR. This bond is absent in inward-facing (‘closed’) zCFTR and in all available hCFTR structures in which the asparagine is replaced by an isoleucine. Moreover, a clear evolutionary trend is observed regarding the latter amino acid change. We thus aim to investigate the role of the N120–S109 interaction, a potential stabilizer of the ‘flickery’ closed state, and its relationship to the stabilizing effect of R117. In hCFTR, introduction of the asparagine caused a large decline in open probability (Po) and mean open time (τo), but an increase in the mean flickery close time (τc) and the mean burst duration (τb). In contrast, elimination of the H-bond in zCFTR by truncation of the asparagine side chain (N120A) increased Po and τo but decreased τc and τb. In conclusion, the N120-S109 interaction indeed stabilizes the ‘flickery’ closed state in zCFTR, and might have played a key role in the development of channel mechanics and pathophysiology. Project was funded by HCEMM and CFF.

University and Doctoral School

Semmelweis University, Doctoral School of Molecular Medicine

Supervisor

László Csanády

Publication of my abstract

I do not give consent to the publication of my abstract on the website of the congress.

Kind

Szabad

Status

elfogadva

Accepted presentation method

poszter

Előadás fájl jóváhagyás

nem rendelkezett róla

Előadó

6065

Start

13:00

End

13:05

Authors (legacy)

Márton A. Simon, László Csanády
Department of Biochemistry, Semmelweis University, Budapest