s Abstract G protein-coupled receptors (GPCRs) represent a major class of proteins in the genome of many species, including humans. In addition to the mapping of a number of human disorders to regions of the genome containing GPCRs, a growing body of literature has documented frequently occurring variations (i.e. polymorphisms) in GPCR loci. In this article, we use a domain-based approach to systematically examine examples of genetic variation in the coding and noncoding regions of GPCR loci. Data to date indicate that residues in GPCRs are involved in ligand binding and coupling to G proteins and that regulation can be altered by polymorphisms. Studies of GPCR polymorphisms have also uncovered the functional importance of residues not previously implicated from other approaches that are involved in the function of GPCRs. We predict that studies of GPCR polymorphisms will have a significant impact on medicine and pharmacology, in particular, by providing new means to subclassify patients in terms of both diagnosis and treatment.

Genes for the principal sigma factor (rpoD genes) of various eubacteria were identified with a synthetic oligonucleotide probe corresponding to a conserved sequence in rpoD gene products of Escherichia coli and Bacillus subtilis. Multiple rpoD homologs were found in the strains of Micrococcus, Pseudomonas, and Streptomyces, whereas single genes were detected in E. coli, B. subtilis, and Staphylococcus aureus. The four rpoD homologs of Streptomyces coelicolor A3(2) were cloned and sequenced. A homologous portion with 13 amino acids was found in the rpoD genes of S. coelicolor A3(2), E. coli, and B. subtilis and was named the "rpoD box."

[1] We estimated the P wave velocity structure of the crust of the subducting Pacific plate beneath northeast Japan using arrival time data of P-to-S-converted waves. The results show that the P wave velocity of the subducting crust varies along the arc and increases abruptly at a depth of~100 km, from 6.5-7.0 km/s in the fore arc to 7.5-8.5 km/s in the back arc. The P wave velocity in the fore arc is~10% lower than theoretically expected values for the metamorphosed mid-ocean ridge basalt material. Seismicity in the subducting crust is most active at depths of 70-80 km where P wave velocities are lowest. The marked reduction of P wave velocity suggests the coexistence of aqueous fluids with hydrous minerals. Abundant fluids elevate pore fluid pressures and reduce effective normal stress, promoting intensive seismic activity in the low-velocity crust. Our observations provide seismic evidence that earthquakes in the subducting crust are facilitated by fluid-related embrittlement. Citation: Shiina, T., J. Nakajima, and T. Matsuzawa (2013), Seismic evidence for high pore pressures in the oceanic crust: Implications for fluid-related embrittlement,

We estimate the three‐dimensional (3‐D) P wave attenuation structure beneath Kyushu, Japan, using a large number of high‐quality waveform data. Our results show that the mantle wedge is characterized by high‐attenuation regions in the fore‐arc corner and in the back‐arc beneath volcanoes, with the two regions separated by a low‐attenuation area. The volcanic gap in central Kyushu is underlain by low attenuation below the Moho. High attenuation in the fore arc is probably associated with serpentinized peridotite, while that in the back arc is interpreted as an upwelling flow that is the source of arc magmas. The presence of low‐attenuation mantle that separates the high‐attenuation hydrated, fore‐arc, and back‐arc mantle regions suggests that fluids are supplied from two depth levels of the slab by different mechanisms. Low attenuation beneath the volcanic gap probably results from intricate 3‐D mantle flow that is caused by tectonic processes such as back‐arc extension and ridge collision.

Eclogitization of the basaltic and gabbroic layer in the oceanic crust involves a volume reduction of 10%-15%. One consequence of the negative volume change is the formation of a paired stress fi eld as a result of strain compatibility across the reaction front. Here we use waveform analysis of a tiny seismic cluster in the lower crust of the downgoing Pacifi c plate and reveal new evidence in favor of this mechanism: tensional earthquakes lying 1 km above compressional earthquakes, and earthquakes with highly similar waveforms lying on welldefi ned planes with complementary rupture areas. The tensional stress is interpreted to be caused by the dimensional mismatch between crust transformed to eclogite and underlying untransformed crust, and the earthquakes are probably facilitated by reactivation of fossil faults extant in the subducting plate. These observations provide seismic evidence for the role of volume change-related stresses and, possibly, fl uid-related embrittlement as viable processes for nucleating earthquakes in downgoing oceanic lithosphere.