Protein semisynthesis underscores the role of a conserved lysine in activation and desensitization of acid-sensing ion channels.
Cell Chem Biol
; 31(5): 1000-1010.e6, 2024 May 16.
Article
em En
| MEDLINE
| ID: mdl-38113885
ABSTRACT
Acid-sensing ion channels (ASICs) are trimeric ion channels that open a cation-conducting pore in response to proton binding. Excessive ASIC activation during prolonged acidosis in conditions such as inflammation and ischemia is linked to pain and stroke. A conserved lysine in the extracellular domain (Lys211 in mASIC1a) is suggested to play a key role in ASIC function. However, the precise contributions are difficult to dissect with conventional mutagenesis, as replacement of Lys211 with naturally occurring amino acids invariably changes multiple physico-chemical parameters. Here, we study the contribution of Lys211 to mASIC1a function using tandem protein trans-splicing (tPTS) to incorporate non-canonical lysine analogs. We conduct optimization efforts to improve splicing and functionally interrogate semisynthetic mASIC1a. In combination with molecular modeling, we show that Lys211 charge and side-chain length are crucial to activation and desensitization, thus emphasizing that tPTS can enable atomic-scale interrogations of membrane proteins in live cells.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Canais Iônicos Sensíveis a Ácido
/
Lisina
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Cell Chem Biol
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
Dinamarca