Combination of MS protein identification and bioassay of chromatographic fractions to identify biologically active substances from complex protein sources.

Purification of biologically active proteins from complex biological sources is a difficult task, usually requiring large amounts of sample and many separation steps. We found an active substance in a serum response element-dependent luciferase reporter gene bioassay in interstitial cystitis urine that we attempted to purify with column chromatography and the bioassay. With anion-exchange Mono Q and C4 reversed-phase columns, apparently sharp active peaks were obtained.

The evolutionarily conserved G protein-coupled receptor SREB2/GPR85 influences brain size, behavior, and vulnerability to schizophrenia.

The G protein-coupled receptor (GPCR) family is highly diversified and involved in many forms of information processing. SREB2 (GPR85) is the most conserved GPCR throughout vertebrate evolution and is expressed abundantly in brain structures exhibiting high levels of plasticity, e.g.

Absence of increased alpha1-microglobulin in IgA nephropathy proteinuria.

To search for biomarkers of IgA nephropathy, protein profiles of urine samples from patients with IgA nephropathy and normal volunteers were compared using two-dimensional DIGE. Most of the 172 spots identified in the urine were serum proteins, and their amounts in IgA nephropathy urine were much higher than those in normal urine; this can be explained as proteinuria caused by glomerular dysfunction. However, only alpha(1)-microglobulin, also one of the major serum proteins, in IgA nephropathy urine was not higher in amount than that in normal urine.

Abnormal development of the olfactory bulb and reproductive system in mice lacking prokineticin receptor PKR2.

Prokineticins, multifunctional secreted proteins, activate two endogenous G protein-coupled receptors PKR1 and PKR2. From in situ analysis of the mouse brain, we discovered that PKR2 is predominantly expressed in the olfactory bulb (OB). To examine the role of PKR2 in the OB, we created PKR1- and PKR2-gene-disrupted mice (Pkr1(-/-) and Pkr2(-/-), respectively).

Molecular cloning of monkey histamine H4 receptor.

Histamine H(4) receptor is considered as a novel therapeutic target for allergic diseases. To enhance the knowledge about species difference, which is essential for drug discovery research, monkey H(4) receptor was identified. Monkey H(4) receptor was characterized to have comparable similarity with its human counterpart.

Molecular cloning and characterization of a novel Gq-coupled orphan receptor GPRg1 exclusively expressed in the central nervous system.

G-protein-coupled receptors (GPCRs) are important mediators of signal transduction and are therefore potential targets for pharmacological therapeutics. Here, we report the identification and characterization of an orphan GPCR, termed GPRg1, which was found in the GenBank database following searches with GPCR query sequences. Quantitative PCR analysis revealed that GPRg1 transcripts are expressed almost exclusively in the brain.