Differential arousal regulation by prokineticin 2 signaling in the nocturnal mouse and the diurnal monkey.

The temporal organization of activity/rest or sleep/wake rhythms for mammals is regulated by the interaction of light/dark cycle and circadian clocks. The neural and molecular mechanisms that confine the active phase to either day or night period for the diurnal and the nocturnal mammals are unclear. Here we report that prokineticin 2, previously shown as a circadian clock output molecule, is expressed in the intrinsically photosensitive retinal ganglion cells, and the expression of prokineticin 2 in the intrinsically photosensitive retinal ganglion cells is oscillatory in a clock-dependent manner.

Expression of prokineticin 2 and its receptor in the macaque monkey brain.

Prokineticin 2 (PK2) has been indicated as an output signaling molecule for the suprachiasmatic nucleus (SCN) circadian clock. Most of these studies were performed with nocturnal animals, particularly mice and rats. In the current study, the PK2 and its receptor, PKR2, was cloned from a species of diurnal macaque monkey.

Rhythmic Trafficking of TRPV2 in the Suprachiasmatic Nucleus is Regulated by Prokineticin 2 Signaling.

The mammalian circadian clock is composed of single-cell oscillators. Neurochemical and electrical signaling among these oscillators is important for the normal expression of circadian rhythms. Prokineticin 2 (PK2), encoding a cysteine-rich secreted protein, has been shown to be a critical signaling molecule for the regulation of circadian rhythms.

Vasopressin receptor V1a regulates circadian rhythms of locomotor activity and expression of clock-controlled genes in the suprachiasmatic nuclei.

The suprachiasmatic nuclei (SCN) serve as the principal circadian pacemakers that coordinate daily cycles of behavior and physiology for mammals. A network of transcriptional and translational feedback loops underlies the operating molecular mechanism for circadian oscillation within the SCN neurons. It remains unclear how timing information is transmitted from SCN neurons to eventually evoke circadian rhythms.

Short term arterial remodelling in the aortae of cholesterol fed New Zealand white rabbits shown in vivo by high-resolution magnetic resonance imaging - implications for human pathology.

High-resolution, non-invasive imaging methods are required to monitor progression and regression of atherosclerotic plaques. We investigated the use of MRI to measure changes in plaque volume and vessel remodelling during progression and regression of atherosclerosis in New Zealand White rabbits. Atherosclerotic lesions were induced in the abdominal aorta by balloon injury and cholesterol feeding.

Differential activation of "social" and "solitary" variants of the Caenorhabditis elegans G protein-coupled receptor NPR-1 by its cognate ligand AF9.

Natural variations of wild Caenorhabditis elegans isolates having either Phe-215 or Val-215 in NPR-1, a putative orphan neuropeptide Y-like G protein-coupled receptor, result in either "social" or "solitary" feeding behaviors (de Bono, M., and Bargmann, C. I.

Cloning and functional expression of the first Drosophila melanogaster sulfakinin receptor DSK-R1.

Described in this report is a successful cloning and characterization of a functionally active Drosophila sulfakinin receptor designated DSK-R1. When expressed in mammalian cells, DSK-R1 was activated by a sulfated, Met(7-->Leu(7)-substituted analog of drosulfakinin-1, FDDY(SO(3)H)GHLRF-NH(2) ([Leu(7)]-DSK-1S). The interaction of [Leu(7)]-DSK-1S with DSK-R1 led to a dose-dependent intracellular calcium increase with an EC(50) in the low nanomolar range.