Microtubule-binding protein MAP1B regulates interstitial axon branching of cortical neurons via the tubulin tyrosination cycle.

Regulation of directed axon guidance and branching during development is essential for the generation of neuronal networks. However, the molecular mechanisms that underlie interstitial (or collateral) axon branching in the mammalian brain remain unresolved. Here, we investigate interstitial axon branching in vivo using an approach for precise labeling of layer 2/3 callosal projection neurons (CPNs).

Drebrin Regulates Collateral Axon Branching in Cortical Layer II/III Somatosensory Neurons.

Proper cortical lamination is essential for cognition, learning, and memory. Within the somatosensory cortex, pyramidal excitatory neurons elaborate axon collateral branches in a laminar-specific manner that dictates synaptic partners and overall circuit organization. Here, we leverage both male and female mouse models, single-cell labeling and imaging approaches to identify intrinsic regulators of laminar-specific collateral, also termed interstitial, axon branching.

Netrin-Mediated Axon Guidance to the CNS Midline Revisited.

Varadarajan et al. (2017)-in this issue of Neuron-and Dominici et al. (2017)-published online at Nature-independently show that floor plate-derived netrin-1 is dispensable for commissural neuron axon guidance to the CNS midline during development.

Axon Dynamics during Neocortical Laminar Innervation.

The cerebral cortex is a densely interconnected structure with neural circuits that form between cortical laminae and also between distinct cortical areas. However, the precise cell biological and developmental mechanisms that underlie the formation of these neural circuits remain unknown. Here, we visualize laminar innervation of the developing mouse cerebral cortex by layer II/III pyramidal neurons in real time, describing cytoskeletal dynamics during this process.

Regulation of iron homeostasis mediated by the heme-binding protein Dap1 (damage resistance protein 1) via the P450 protein Erg11/Cyp51.

Fungal infections arise frequently in immunocompromised patients, and sterol synthesis is a primary pathway targeted by antifungal drugs. In particular, the P450 protein Erg11/Cyp51 catalyzes a critical step in ergosterol synthesis, and the azole class of antifungal drugs inhibits Erg11. Dap1 is a heme-binding protein related to cytochrome b5 that activates Erg11, so that cells lacking Dap1 accumulate the Erg11 substrate and are hypersensitive to Erg11 inhibitors.

Hpr6.6 protein mediates cell death from oxidative damage in MCF-7 human breast cancer cells.

Reactive oxygen species (ROS) cause cell death and are associated with a variety of maladies, from trauma and infection to organ degeneration and cancer. Cells mount a complex response to oxidative damage that includes signaling from transmembrane receptors and intracellular kinases. We have analyzed the response to oxidative damage in human breast cancer cells expressing the Hpr6.

Overexpression of the receptor tyrosine kinase Tie-1 intracellular domain in breast cancer.

Objective: Tyrosine kinase with immunoglobulin and epidermal growth factor homology domains (Tie-1) is a receptor tyrosine kinase that regulates angiogenesis and antiapoptotic survival signaling. Tie-1 expression is generally associated with endothelial cells and neovascularization. We previously identified Tie-1 in human breast tumor samples using a PCR-based screen for protein kinases expressed in breast tumors.

Saccharomyces cerevisiae Dap1p, a novel DNA damage response protein related to the mammalian membrane-associated progesterone receptor.

The response to damage is crucial for cellular survival, and eukaryotic cells require a broad array of proteins for an intact damage response. We have found that the YPL170W (DAP1 [for damage response protein related to membrane-associated progesterone receptors]) gene is required for growth in the presence of the methylating agent methyl methanesulfonate (MMS). The DAP1 open reading frame shares homology with a broadly conserved family of membrane-associated progesterone receptors (MAPRs).