The calmodulin-binding tetraleucine motif of KCNE4 is responsible for association with Kv1.3.
FASEB J
; 33(7): 8263-8279, 2019 07.
Article
en En
| MEDLINE
| ID: mdl-30969795
ABSTRACT
The voltage-dependent potassium (Kv) channel Kv1.3 regulates leukocyte proliferation, activation, and apoptosis, and altered expression of this channel is linked to autoimmune diseases. Thus, the fine-tuning of Kv1.3 function is crucial for the immune system response. The Kv1.3 accessory protein, potassium voltage-gated channel subfamily E (KCNE) subunit 4, acts as a dominant negative regulatory subunit to both enhance inactivation and induce intracellular retention of Kv1.3. Mutations in KCNE4 also cause immune system dysfunction. Although the formation of Kv1.3-KCNE4 complexes has profound consequences for leukocyte physiology, the molecular determinants involved in the Kv1.3-KCNE4 association are unknown. We now show that KCNE4 associates with Kv1.3 via a tetraleucine motif situated within the carboxy-terminal domain of this accessory protein. This motif would function as an interaction platform, in which Kv1.3 and Ca2+/calmodulin compete for the KCNE4 interaction. Finally, we propose a structural model of the Kv1.3-KCNE4 complex. Our experimental data and the in silico structure suggest that the KCNE4 interaction hides a forward-trafficking motif within Kv1.3 in addition to adding a strong endoplasmic reticulum retention signature to the Kv1.3-KCNE4 complex. Thus, the oligomeric composition of the Kv1.3 channelosome fine-tunes the precise balance between anterograde and intracellular retention elements that control the cell surface expression of Kv1.3 and immune system physiology.-Solé, L., Roig, S. R., Sastre, D., Vallejo-Gracia, A., Serrano-Albarrás, A., Ferrer-Montiel, A., Fernández-Ballester, G., Tamkun, M. M., Felipe, A. The calmodulin-binding tetraleucine motif of KCNE4 is responsible for association with Kv1.3.
Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Canales de Potasio con Entrada de Voltaje
/
Canal de Potasio Kv1.3
/
Leucocitos
Tipo de estudio:
Risk_factors_studies
Límite:
Animals
/
Humans
Idioma:
En
Revista:
FASEB J
Asunto de la revista:
BIOLOGIA
/
FISIOLOGIA
Año:
2019
Tipo del documento:
Article
País de afiliación:
España