We have recently identified from the avian hypothalamus a complementary DNA encoding a small secretory protein termed neurosecretory protein GL (NPGL). In chicks, NPGL increases body weight gain without affecting food intake. A database search reveals that NPGL is conserved throughout vertebrates. However, the central distribution and functional role of NPGL remains to be elucidated in mammals. In this study, we identified the precursor complementary DNA encoding NPGL from the mouse hypothalamus. Quantitative reverse transcription polymerase chain reaction and morphological analyses revealed that NPGL precursor messenger RNA is robustly expressed in the mediobasal hypothalamus with NPGL neurons specifically localized to the lateroposterior part of the arcuate nucleus in the hypothalamus. NPGL-immunoreactive fibers were observed in close anatomical contact with pro-opiomelanocortin neurons in the rostral region of the arcuate nucleus. NPGL messenger RNA expression was elevated by 24-hour fasting and reduced by feeding of a high-fat diet for 5 weeks. Furthermore, intracerebroventricular injection of mature NPGL increased food intake, pointing to an important role in feeding. Taken together, these findings report on the distribution of NPGL in the mammalian brain and point to an important role for this neuropeptide in energy homeostasis.

Polystyrene honeycomb scaffolds with different pore sizes were successfully fabricated by casting a polymer solution under humid conditions in order to investigate the effect of porous microtopography on hMSC differentiation. We have used honeycomb scaffolds to achieve the microtopography-induced differentiation of hMSCs. Honeycomb scaffolds led hMSCs to osteospecific and myospecific differentiations depending on the size of pores. This selective differentiation suggested that surface microtopography alone may be effective for using hMSCs in regenerative medicine and tissue engineering.

The WW domain is known as one of the smallest protein modules with a triple-stranded b-sheet fold. Here, we present the solution structure of the second WW domain from the mouse salvador homolog 1 protein. This WW domain forms a homodimer with a b-clam-like motif, as evidenced by size exclusion chromatography, analytical ultracentrifugation and NMR spectroscopy. While typical WW domains are believed to function as monomeric modules that recognize proline-rich sequences, by using conserved aromatic and hydrophobic residues that are solvent-exposed on the surface of the b-sheet, this WW domain buries these residues in the dimer interface.

The acid-treated single-walled carbon nanotubes (SWCNTs) dispersed in water are only kinetically stable with electrostatic double layer repulsions just balancing against van der Waals (VDW) attractions. Introducing any external factor to disturb this balance causes immediate coagulation of SWCNTs. Here, an amine-covered flat substrate was immersed in the dispersion to initiate adsorption of SWCNTs onto the substrate surface. By repeating an adsorption-rinse-dry cycle, it was possible to deposit SWCNT bundles in a layer-by-layer fashion and to develop a 2D network consisting only of SWCNTs that are held by VDW interaction. We show that (1) adsorbed solution-grown aggregates are not relevant for the network connectivity, (2) 2D percolation takes place at very low surface coverage, (3) the electrical resistivity follows a power law against the layering cycles, (4) not only the adsorbed amount but also the added amount per layering cycle increases linearly with the SWCNT concentration, and (5) after the adsorption is initiated by amines, VDW attraction takes over for subsequent adsorption, with the consequence that the newly adsorbed SWCNTs are used to thicken each arm of the network rather than to cover more free surfaces.

Actin is one of the most conserved proteins in nature. Its assembly and disassembly are regulated by many proteins, including the family of actin-depolymerizing factor homology (ADF-H) domains. ADF-H domains can be divided into five classes: ADF/cofilin, glia maturation factor (GMF), coactosin, twinfilin, and Abp1/drebrin. The best-characterized class is ADF/cofilin. The other four classes have drawn much less attention and very few structures have been reported. This study presents the solution NMR structure of the ADF-H domain of human HIP-55-drebrin-like protein, the first published structure of a drebrin-like domain (mammalian), and the first published structure of GMF b (mouse). We also determined the structures of mouse GMF c, the mouse coactosin-like domain and the C-terminal ADF-H domain of mouse twinfilin 1. Although the overall fold of the five domains is similar, some significant differences provide valuable insights into filamentous actin (F-actin) and globular actin (G-actin) binding, including the identification of binding residues on the long central helix. This long helix is stabilized by three or four residues. Notably, the F-actin binding sites of mouse GMF b and GMF c contain two additional b-strands not seen in other ADF-H structures. The G-actin binding site of the ADF-H domain of human HIP-55-drebrin-like protein is absent and distorted in mouse GMF b and GMF c.