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Peter Simpson

Publications and source records attributed to Peter Simpson.

27 records · Page 2Linked to original sources

Solution structure and RNA interactions of the RNA recognition motif from eukaryotic translation initiation factor 4B.

Eukaryotic initiation factor 4B (eIF4B) is a multidomain protein with a range of activities that serves primarily to promote association of messenger RNA to the 40S ribosomal subunit during translation initiation. We report here the solution structure of the eIF4B RNA recognition motif (RRM) domain. It adopts a classical RRM fold, with a beta alpha beta beta alpha beta topology. The most striking difference with other RRM structures is in the disposition of loop 3, which connects the beta 2 and beta 3 strands and is implicated in RNA recognition. This loop folds down against the body of the RRM and exhibits restricted motion on a milli- to microsecond time scale. Although it contributes to a large basic patch on the RNA binding surface, it does not protrude out from the domain as observed in other RRM structures, possibly implying a different mode of RNA binding. On its own, the core RRM domain provides only a relative weak interaction with RNA targets and appears to require extensions at the N- and C-terminus for high-affinity binding.

Amino Acid Motifs↗

cDNA microarray analysis of genes associated with ERBB2 (HER2/neu) overexpression in human mammary luminal epithelial cells.

To investigate changes in gene expression associated with ERBB2, expression profiling of immortalized human mammary luminal epithelial cells and variants expressing a moderate and high level of ERBB2 has been carried out using cDNA microarrays corresponding to approximately 6000 unique genes/ESTs. A total of 61 significantly up- or downregulated (2.0-fold) genes were identified and further validated by RT-PCR analysis as well as microarray comparisons with a spontaneously ERBB2- overexpressing breast cancer cell line and ERBB2-positive primary breast tumors. The expression and clinical relevance of proteins predicted to be associated with ERBB2 overexpression in breast cancers were analysed together with their clinical relevance by antibody screening using a tissue array. Differentially regulated genes include those involved in cell-matrix interactions including proline 4-hydroxylase (P4HA2), galectin 1 (LGALS1) and galectin 3 (LGALS3), fibronectin 1 (FN1) and p-cadherin (CDH3), and cell proliferation (CRIP1, IGFBP3) and transformation (S100P, S100A4). A number of genes associated with MYC signalling were also differentially expressed, including NDRG1, USF2 and the epithelial membrane proteins 1 and 3 (EMP1, EMP3). These data represent profiles of the transcriptional changes associated with ERBB2-related pathways in the breast, and identify novel and potentially useful targets for prognosis and therapy.

Breast↗

Origin and subset distribution of peripheral blood dendritic cells in patients with chronic graft-versus-host disease.

BACKGROUND: After allogeneic hematopoietic stem cell transplantation, donor T cells interact with an antigen-presenting cell environment that is distorted in number, level of activation, and origin. The role of antigen presentation in the development of chronic graft-versus host disease (cGVHD) is unknown. METHODS: The number and origin of peripheral blood immature myeloid (CD19- CD1c+) and plasmacytoid (BDCA-2+) dendritic cells (DCs) was determined in 30 patients at more than 100 days after allogeneic hematopoietic stem cell transplantation. RESULTS: Patients with cGVHD had significantly higher plasmacytoid DC numbers than individuals without this complication (9.1+/-2.0 x 10(6)/L versus 3.8+/-0.6 x 10(6)/L, =0.025). Chimerism studies demonstrated that DCs in patients with cGVHD were exclusively of donor origin, whereas persistence of host DCs was observed in some control patients. CONCLUSIONS: The antigen-presenting cell environment in patients with cGVHD, as represented by immature blood DCs, is of donor origin but distorted in terms of subset distribution.

Adolescent↗