Speaker: John R. Yates, The Scripps Research Institute

Topic: How a single mutation in CFTR causes the systemic disease cystic fibrosis: interactions, PTMs, and structure

Date: Monday, September 11, 2023

Time: 6:00 pm Dinner and Vendor Night, 7:15 pm Presentation

Location: Shimadzu Scientific Instrument, Inc. Training Center 7100 Riverwood Drive, Columbia, MD 21046 (Directions) This will be an in-person meeting.

Dinner: Please RSVP to Jonathan Ferguson (jonathan.ferguson33@gmail.com) by Friday, September 8 if you will be attending the dinner.

Abstract: Protein conformation is dynamic as it is influenced by post-translational modifications (PTMs) and interactions with other proteins, small molecules or RNA, for example. However, in vivo characterization of protein structures and protein structural changes after perturbation is a major challenge. Therefore, experiments to characterize protein structures are typically performed in vitro and with highly purified proteins or protein
complexes, revealing a static picture of the protein. To identify the true conformational space occupied by proteins in vivo, we developed a novel low-resolution method named Covalent Protein Painting (CPP) that allows the characterization of protein conformations in vivo. Here, we report how an ion channel, the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR), is conformationally changed during biogenesis and channel opening in the cell. Our study led to the identification of a novel opening mechanism for CFTR by revealing that the interaction of the intracellular loop 2 (ICL2) with the nucleotide binding domain 2 (NDB2) of CFTR is needed for channel gating, and this interaction occurs concomitantly with changes to the narrow part of the pore and the walker A lysine in NBD1 for wt CFTR. However, the ICL2:NBD2 interface, which forms a “ball-in-a-socket” motif, is uncoupled during biogenesis, likely to prevent inadvertent channel activation during transport. Mutation of K273 in the ICL2 loop severely impaired CFTR biogenesis and led to accumulation of CFTR in the Golgi and TGN. CPP further revealed that, even upon treatment with current approved drugs such as Trikafta or at permissive temperature, the uncoupled state of ICL2 is a prominent feature of the misfolded CFTR mutants ∆F508 and N1303K that cause Cystic Fibrosis (CF). Although Trikafta treatment reduced the amount of uncoupled ICL2:NBD2 interfaces, more than 75% of F508 CFTR remained in the uncoupled state, suggesting that stabilization of this interface could produce a more efficient CF drug. CPP can characterize a protein in its native environment and measure the effect of complex PTMs and protein interactions on protein structure, making it broadly applicable and valuable for the development of new therapies.
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The Washington-Baltimore Mass Spectrometry Discussion Group is pleased to announce that our first event of 2023-2024 will be kicked off on September 11, 2023 (Monday) at Shimadzu Scientific in Columbia, MD. It is our true privilege this year that a giant in our field, Dr. John Yates III from Scripps Research, will be speaking as the keynote speaker at this event.

Our WBMSDG board has decided to include two lightning talks before the main talk starting with our October event. Each lightning talk lasts 7 minutes with no more than 5 slides, and 5 minutes for Q&A for both talks. The desired speakers are early-career researchers/scientists in mass spec-related areas. They can be junior scientists, postdoctoral fellows, graduate or undergraduate students.

Please submit abstracts to co-chairs to apply for the lightning talks, and our board members will review the abstracts on a rolling basis.

Structure the abstract (maximum 300 words) with the following headings:
Title (maximum 20 words)
Authors and affiliations (Including senior authors/PIs)
Introduction
Methods
Results
Conclusions

(We are updating our sponsors list for 2023-2024.)