Determining Functional KCNQ1/KCNE1 Subunit Interactions in the KCNQ1/KCNE1 Channel

Determining the Molecular Mechanism Modulating Interactions Between Cardiac Potassium Channel α-Subunit Proteins hERG and KvLQT1

Heterodimeric amino acid transporter glycoprotein domains determining functional subunit association.

The heteromeric amino acid transporter glycoprotein subunits rBAT and 4F2hc (heavy chains) form, with different catalytic subunits (light chains), functional heterodimers that are covalently stabilized by a disulphide bridge. Whereas rBAT associates with b(0,+)AT to form the cystine and cationic amino acid transporter defective in cystinuria, 4F2hc associates with other homologous light chains,...

Recruitment interactions can override catalytic interactions in determining the functional identity of a protein kinase.

The yeast Saccharomyces cerevisae has four distinct mitogen-activated protein kinase kinases (MAPKKs), each of which has a distinct functional identity characterized by communication with specific upstream and downstream partners to form distinct functional pathways. These four kinases belong to one family, sharing closely related catalytic domains. How have these four related kinases diverged ...

Using fluorescence to understand β subunit–NaV channel interactions

The human voltage-gated sodium channel NaV1.5 plays a critical role in the human heart, in which it generates inward sodium currents that underlie cardiomyocyte depolarization. The NaV1.5 protein is composed of more than 2,000 amino acids, organized into four homologous domains (Catterall et al., 2017), which equip the channel with one central pore domain and four peripheral voltage sensor doma...

Functional Interactions between KCNE1 C-Terminus and the KCNQ1 Channel

The KCNE1 gene product (minK protein) associates with the cardiac KvLQT1 potassium channel (encoded by KCNQ1) to create the cardiac slowly activating delayed rectifier, I(Ks). Mutations throughout both genes are linked to the hereditary cardiac arrhythmias in the Long QT Syndrome (LQTS). KCNE1 exerts its specific regulation of KCNQ1 activation via interactions between membrane-spanning segments...