Using an affinity resin and photoaffinity label based on phospholipid analogs of inositol 1,3,4,5-tetrakisphosphate (InsP 4 ), we have isolated, characterized, and cloned a 46-kDa protein from rat brain, which we have named centaurin-␣. Binding specificity was determined using displacement of 1-O- Receptor-stimulated phosphoinositide (PI) 1 metabolism generates numerous inositol polyphosphates (InsP n s) and inositol phospholipids, many of which may function as potential second messengers (1). Of the possible PI metabolites, Ins(1,4,5)P 3 (InsP 3 ) and diacylglycerol (DAG) are the best characterized second messengers. Generated by receptor-stimulated phospholipase C, hydrolysis of PtdIns(4,5)P 2 (2), Ins(1,4,5)P 3 binds to and gates an InsP 3 receptor calcium channel on the endoplasmic reticulum (2, 3). The lipid DAG remains in the membrane where it activates several protein kinase C isoforms and may regulate other targets (4, 5). In the membrane, DAG is metabolized rapidly to monoacylglycerol and to several phospholipids. In the cytoplasm, Ins(1,4,5)P 3 can be phosphorylated to Ins(1,3,4,5)P 4 by an InsP 3 3-kinase. Other isomers of InsP 4 , InsP 5 , and InsP 6 , some of which are synthesized independently of Ins(1,4,5)P 3 , have been identified (for review, see Ref. 6), and their production may also be regulated by receptors or during cell growth. Information from receptor binding studies, using radioactive InsP 4 and InsP 6 , have demonstrated that a number of important regulatory proteins contain high affinity InsP n binding sites. InsP n s have been implicated in the regulation of clathrin assembly proteins AP-2 (7, 8), AP-3 (9), the non-clathrin-associated coatomer proteins (10), synaptotagmin (11), and the regulation of the small GTPases ras and/or rap via a specific GTPase-activating protein (GAP) activity (12). Inositol phospholipids have also been postulated as messenger molecules. From in vivo, genetic, and permeabilized cell studies, evidence for critical roles for the inositol phospholipids PtdIns(3)P, PtdIns(4)P, and PtdIns(4,5)P 2 as regulators of membrane vesicle trafficking and cytoskeletal rearrangements is accumulating rapidly (5, 13-15). One inositol phospholipid, PtdIns(3,4,5)P 3 , has emerged as a potential messenger molecule in receptor-stimulated cells (16 -18). Synthesized by receptor-stimulated PI 3-kinase phosphorylation of PtdIns(4,5)P 2 (18), PtdInsP 3 is not a substrate for PI-specific phospholipase * This work was supported in part by National Institutes of Mental Health Grants R29MH50102 and DDRC P50HD32901 (to A. B. T.). Work at Stony Brook was supported by National Institutes of Health Grant NS29632 (to G. D. P.). The first two authors contributed equally to this study. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.The nucleotide sequence(s) reported in this paper has been submitted to the GenBank § §...

Whole-genome sequencing, particularly in fungi, has progressed at a tremendous rate. More difficult, however, is experimental testing of the inferences about gene function that can be drawn from comparative sequence analysis alone. We present a genome-wide functional characterization of a sequenced but experimentally understudied budding yeast, Saccharomyces bayanus var. uvarum (henceforth referred to as S. bayanus), allowing us to map changes over the 20 million years that separate this organism from S. cerevisiae. We first created a suite of genetic tools to facilitate work in S. bayanus. Next, we measured the gene-expression response of S. bayanus to a diverse set of perturbations optimized using a computational approach to cover a diverse array of functionally relevant biological responses. The resulting data set reveals that gene-expression patterns are largely conserved, but significant changes may exist in regulatory networks such as carbohydrate utilization and meiosis. In addition to regulatory changes, our approach identified gene functions that have diverged. The functions of genes in core pathways are highly conserved, but we observed many changes in which genes are involved in osmotic stress, peroxisome biogenesis, and autophagy. A surprising number of genes specific to S. bayanus respond to oxidative stress, suggesting the organism may have evolved under different selection pressures than S. cerevisiae. This work expands the scope of genome-scale evolutionary studies from sequence-based analysis to rapid experimental characterization and could be adopted for functional mapping in any lineage of interest. Furthermore, our detailed characterization of S. bayanus provides a valuable resource for comparative functional genomics studies in yeast.

This essay compares the approaches that scientific societies in the ACCESS meta-organization use to implement and assess travel award programs for URM trainees and presents a set of recommendations, including both short- and long-term outcomes assessment in populations of interest and specialized programmatic activities coupled to travel award programs.