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Biomedical subjects

Nathalie Neyroud

Publications and source records attributed to Nathalie Neyroud.

4 recordsLinked to original sources
PubMed2005

Heart rate influences on repolarization duration and morphology in symptomatic versus asymptomatic KCNQ1 mutation carriers.

QT and Tp/Te intervals were longer in patients with LQT1 (n = 67) than in nonaffected subjects (n = 52) but did not differentiate symptomatic (n = 21) from asymptomatic patients (n = 46). At fast heart rate, the time to accumulate the last part of total T-wave area (the t50-97 interval) was longer in symptomatic carriers compared with asymptomatic patients (119 +/- 19 vs 106 +/- 15 ms, p <0.01). The latter group had significantly longer t50-97 intervals than nonaffected subjects (96 +/- 14 ms, p <0.01).

Adolescent↗
PubMed2004

[MAGUKs: beyond ionic channel anchoring].

A family of anchoring proteins named MAGUK (for membrane associated guanylate kinase) has emerged as a key element in the organization of protein complexes in specialized membrane regions. These proteins are characterized by the presence of multipe protein-protein interaction domains including PDZ and SH3 domains. The MAGUK family comprises the post-synaptic density 95 (PSD-95) protein and closely related molecules such as chapsyn-110, synapse-associated protein 102 (SAP-102), and SAP-97. These are located either on the pre- and/or post-synaptic sides of synapses or at cell-cell adhesion sites of epithelial cells. MAGUK proteins interact with glutamate receptors and various ionic channels. For instance, an interaction has been reported between the first two PDZ domains of MAGUK proteins and several channels via a consensus sequence Thr/Ser-X-Val/Leu usually located at their carboxy terminus. The role of these anchoring proteins in channel function is not fully understood. MAGUK proteins enhance the current density by increasing the number of functional channels to the sarcolemma. They can also facilitate signaling between channels and several enzymes or G protein-dependent signaling pathways. In the heart also, MAGUK proteins are abundantly expressed and they interact with various channels including Shaker Kv1.5 and connexins.

Animals↗
PubMed2002

Isoform-specific modulation of voltage-gated Na(+) channels by calmodulin.

Calmodulin (CaM) is a calcium-sensing protein that binds to Na(+) channels, with unknown functional consequences. Wild-type CaM produced a hyperpolarizing shift in the steady-state availability of expressed skeletal muscle (micro1) but not cardiac (hH1) Na(+) channels. Mutant CaM(1234) did not alter the voltage dependence or the kinetics of gating of either micro1 or hH1. Mutation of the highly conserved IQ motif in the carboxyl terminus of both isoforms (IQ/AA) slowed the kinetics of current decay and abolished the effect of wild-type CaM on micro1, but did not alter hH1 currents. The IQ/AA mutation eliminated CaM binding to the carboxyl terminus of both micro1 and hH1 channels. Inhibition of Ca(2+)/CaM kinase (CaM-K) slowed the current decay, the rate of entry into inactivation, and shifted the voltage dependence of hH1 in the depolarizing direction independent of CaM overexpression with no effect on micro1 Na(+) channels. CaM signaling modulates Na(+) currents in an isoform-specific manner, via direct interaction with skeletal muscle Na(+) channels and through CaM-K in the case of the cardiac isoform. The full text of this article is available at http://www.circresaha.org.

Amino Acid Motifs↗