Worcester Foundation for Biomedical Research

About: Worcester Foundation for Biomedical Research is a based out in . It is known for research contribution in the topics: Estrone & Estrogen. The organization has 2195 authors who have published 2646 publications receiving 115809 citations. The organization is also known as: Worcester Foundation for Experimental Biology.

Isolation and characterization of ribonucleoprotein particles containing heterogeneous nuclear RNA.

Abstract: Publisher Summary This chapter describes methods for the isolation of these ribonucleoprotein (RNP) particles from eukaryotic cells and discusses some properties of heterogeneous nuclear RNA (hnRNA) particles isolated from HeLa cell nuclei. RNP particles containing hnRNA have been identified both cytologically and biochemically in eukaryotic cell nuclei. The method developed for isolation of HeLa hnRNP particles involves the isolation of nuclei followed by their mechanical disruption and purification of hnRNP particles by sucrose gradient centrifugation. The method of disrupting HeLa cell nuclei permits the high recovery of heterogeneous nuclear RNA in the presence of large amounts of nucleohistone. An understanding of the specificity of RNA-protein interactions in native hnRNP particles is impeded by the nucleotide sequence complexity of hnRNA and by the analytical complexity of the proteins. The specific association of protein with poly (A)-rich hnRNA sequences is demonstrated.

Use of Isolated Membrane Vesicles in Transport Studies

Abstract: Isolated membrane vesicles represent one of the simplest systems in which the transport processes remain intact and have therefore provided considerable information on the structure, function, and regulation of transport systems. Although whole cells may also be used for transpprt studies, it is often difficult to separate transport from subsequent events in intracellular intermediary metabolism. One of the important advantages offered by membrane vesicles is the opportunity to investigate their transport functions apart from other cellular activities. At the same time, the isolated transport systems of membrane vesicles are retained in a functional form and their relationship to other membrane components can also be studied.

Effects of ethanol on early potassium currents in Aplysia: cell specificity and influence of channel state.

Abstract: The effects of ethanol (EtOH) on the early potassium current, IA, were examined in 3 identified neurons of Aplysia using voltage-clamp techniques. The primary effect of EtOH on this current was a pronounced increase in the time constant of decay. However, this effect was cell specific, being evident in cells MCC and R15 but not in cell B1. Other parameters of IA were not greatly affected in any of the cells, in comparison with the effects on decay time constant. Baseline parameters of IA were measured in each of the cells to determine whether subpopulations of IA channel might exist, and be differentially sensitive to EtOH. While differences did appear among cells, they were not consistent with an explanation of EtOH's actions based upon distribution of channel subtypes. The effect of EtOH on IA decay was dependent upon the voltage-clamp protocol used. When inactivation of IA developed at -20 mV, the slower development of inactivation noted above occurred. When inactivation without channel opening was produced by means of a prepulse to -40 mV, EtOH speeded up the development of inactivation. A number of possible explanations for these findings are discussed. Most of the effects of EtOH occurred within 1 min of application of the drug, suggesting relatively rapid access to the site of action. Effects continued to develop over succeeding minutes. This slower-developing effect may reflect either a delayed access to channels due to slower diffusion into or lateral movement within the lipid phase of the membrane, or it may indicate that channels are accessible to the EtOH molecule only when in certain states.

Expression of a Drosophila melanogaster acetylcholine receptor-related gene in the central nervous system.

Abstract: We isolated Drosophila melanogaster genomic sequences with nucleotide and amino acid sequence homology to subunits of vertebrate acetylcholine receptor by hybridization with a Torpedo acetylcholine receptor subunit cDNA probe. Five introns are present in the portion of the Drosophila gene encoding the unprocessed protein and are positionally conserved relative to the human acetylcholine receptor alpha-subunit gene. The Drosophila genomic clone hybridized to salivary gland polytene chromosome 3L within region 64B and was termed AChR64B. A 3-kilobase poly(A)-containing transcript complementary to the AChR64B clone was readily detectable by RNA blot hybridizations during midembryogenesis, during metamorphosis, and in newly enclosed adults. AChR64B transcripts were localized to the cellular regions of the central nervous system during embryonic, larval, pupal, and adult stages of development. During metamorphosis, a temporal relationship between the morphogenesis of the optic lobe and expression of AChR64B transcripts was observed.