Cardiac-specific ablation of synapse-associated protein SAP97 in mice decreases potassium currents but not sodium current.

Background: Membrane-associated guanylate kinase (MAGUK) proteins are important determinants of ion channel organization in the plasma membrane. In the heart, the MAGUK protein SAP97, encoded by the DLG1 gene, interacts with several ion channels via their PDZ domain-binding motif and regulates their function and localization.

Objective: The purpose of this study was to assess in vivo the role of SAP97 in the heart by generating a genetically modified mouse model in which SAP97 is suppressed exclusively in cardiomyocytes.

PDZ domain-binding motif regulates cardiomyocyte compartment-specific NaV1.5 channel expression and function.

Background: Sodium channel NaV1.5 underlies cardiac excitability and conduction. The last 3 residues of NaV1.

NaV1.5 and interacting proteins in human arrhythmogenic cardiomyopathy.

Evaluation of: Noorman M, Hakim S, Kessler E et al. Remodeling of the cardiac sodium channel, connexin43, and plakoglobin at the intercalated disk in patients with arrhythmogenic cardiomyopathy. Heart Rhythm 10(3), 412-419 (2013).

Cardiac sodium channel NaV1.5 distribution in myocytes via interacting proteins: the multiple pool model.

The cardiac sodium current (INa) is responsible for the rapid depolarization of cardiac cells, thus allowing for their contraction. It is also involved in regulating the duration of the cardiac action potential (AP) and propagation of the impulse throughout the myocardium. Cardiac INa is generated by the voltage-gated Na(+) channel, NaV1.

Patterns of growth, axonal extension and axonal arborization of neuronal lineages in the developing Drosophila brain.

The Drosophila central brain is composed of approximately 100 paired lineages, with most lineages comprising 100-150 neurons. Most lineages have a number of important characteristics in common. Typically, neurons of a lineage stay together as a coherent cluster and project their axons into a coherent bundle visible from late embryo to adult.

Specification and development of the pars intercerebralis and pars lateralis, neuroendocrine command centers in the Drosophila brain.

The central neuroendocrine system in the Drosophila brain includes two centers, the pars intercerebralis (PI) and pars lateralis (PL). The PI and PL contain neurosecretory cells (NSCs) which project their axons to the ring gland, a complex of peripheral endocrine glands flanking the aorta. We present here a developmental and genetic study of the PI and PL.

Embryonic origin of the Drosophila brain neuropile.

Neurons of the Drosophila larval brain are formed by a stereotyped set of neuroblasts. As differentiation sets in, neuroblast lineages produce axon bundles that initially form a scaffold of unbranched fibers in the center of the brain primordium. Subsequently, axons elaborate interlaced axonal and dendritic arbors, which, together with sheath-like processes formed by glial cells, establish the neuropile compartments of the larval brain.

Morphogenesis and proliferation of the larval brain glia in Drosophila.

Glial cells subserve a number of essential functions during development and function of the Drosophila brain, including the control of neuroblast proliferation, neuronal positioning and axonal pathfinding. Three major classes of glial cells have been identified. Surface glia surround the brain externally.

Antagonistic relationship between Dpp and EGFR signaling in Drosophila head patterning.

The Drosophila eye field that gives rise to the visual system and dorsal head epidermis forms an unpaired anlage located in the dorsal head ectoderm. The eye field expresses and requires both Dpp and EGFR signaling for its development. As shown in previous studies, EGFR is required for cell maintenance in the developing visual system.

Interaction between EGFR signaling and DE-cadherin during nervous system morphogenesis.

Dynamically regulated cell adhesion plays an important role during animal morphogenesis. Here we use the formation of the visual system in Drosophila embryos as a model system to investigate the function of the Drosophila classic cadherin, DE-cadherin, which is encoded by the shotgun (shg) gene. The visual system is derived from the optic placode which normally invaginates from the surface ectoderm of the embryo and gives rise to two separate structures, the larval eye (Bolwig's organ) and the optic lobe.