Search PubMed⌕ Search

Biomedical subjects

B J O'Sullivan

Publications and source records attributed to B J O'Sullivan.

8 recordsLinked to original sources
PubMed2000

RelB nuclear translocation regulates B cell MHC molecule, CD40 expression, and antigen-presenting cell function.

Mice with targeted RelB mutations demonstrated an essential role for RelB in immune responses and in myeloid dendritic cell differentiation. Human studies suggested a more global transcriptional role in antigen presentation. Burkitt lymphoma cell lines were used as a model to examine the role of RelB in antigen presentation. After transient transfection of BJAB with RelB, strong nuclear expression of RelB-p50 heterodimers was associated with increased APC function and expression of CD40 and MHC class I. Antisense RelB in DG75 reduced antigen-presenting capacity and CD40-mediated up-regulation of MHC molecules. The data indicate that RelB transcriptional activity directly affects antigen presentation and CD40 synthesis. Stimulation of RelB transcriptional activity may provide a positive feedback loop for facilitating productive APC/T cell interactions.

Antigen-Presenting Cells↗
PubMed1995

Chromosomal structure of the human TYRP1 and TYRP2 loci and comparison of the tyrosinase-related protein gene family.

The structures of the human tyrosinase-related protein genes TYRP1 and TYRP2 have been determined and compared with that of the tyrosinase gene (TYR). The TYRP1 protein is encoded in 7 exons spread over 24 kb of genomic DNA. Characterization of a 55-kb contig encompassing the human TYRP2 locus reveals that the protein coding region is divided into 8 exons. All three members of the TYRP gene family share a common C-terminal membrane spanning exon. Examination of the position of other intron junctions suggests that TYRP1 was derived from a TYR duplication and then was itself duplicated to give rise to the TYRP2 gene. The evidence also suggests that at least some of the introns within the TYR, TYRP1, and TYRP2 coding regions were gained after duplication and that intron slippage is unlikely to have occurred.

Amino Acid Sequence↗
PubMed1994

Expression studies of pigmentation and POU-domain genes in human melanoma cells.

Human melanoma cell lines have been used to examine the regulation of the tyrosinase (TYR) and tyrosinase-related protein genes TRP-1 and TRP-2 in response to differentiating chemicals and UV irradiation. TRP-1 mRNA levels can be repressed by treatment with the differentiating chemicals DMSO and HMBA. There is little effect of UV irradiation on pigment synthesis by human melanoma cell lines or tyrosinase activity, with variable effects on the levels of the TYR, TRP-1, and TRP-2 gene transcripts. The human TRP-1 gene promoter has been isolated and its activity tested by transient cell transfection to begin an examination of signal transduction mechanisms operating in response to pigmenting and differentiating agents. To identify transcription factors that may be involved in melanocytic gene expression, we studied the N-Oct-3 and N-Oct-5 octamer-binding activities normally expressed in the neuroectodermal cell lineage and which are expressed at high levels in melanoma cells. POU-domain-containing cDNA have been isolated from the A2058 human melanoma cell line that are homologous to the brn-2 gene that encodes N-Oct-3 and N-Oct-5.

Acetamides↗
PubMedDate not supplied

Duplication (12p) syndrome--a family.

We report the following cases of Duplication (12p) Syndrome. This is a rare entity which may present with developmental delay, dysmorphic features and malformations.

Chromosome Aberrations↗