Oligogenic combinations associated with breast cancer risk in women under 53 years of age.

Common, but weakly penetrant, functional polymorphisms probably account for most of the genetic risk for breast cancer in the general population. Current polygenic risk models assume that component genes act independently. To test for potential gene-gene interactions, single nucleotide polymorphisms in ten genes with known or predicted roles in breast carcinogenesis were examined in a case-control study of 631 Caucasian women diagnosed with breast cancer under the age of 53 years and 1,504 controls under the age of 53 years.

Conversion of a cosubstrate to an inhibitor: phosphorylation mutants of nicotinic acid phosphoribosyltransferase.

Nicotinic acid phosphoribosyltransferase (NAPRTase; EC 2.4.2.

Histones H3 and H4 are components of upstream activation factor required for the high-level transcription of yeast rDNA by RNA polymerase I.

RNA polymerase I (Pol I) transcription in the yeast Saccharomyces cerevisiae is greatly stimulated in vivo and in vitro by the multiprotein complex, upstream activation factor (UAF). UAF binds tightly to the upstream element of the rDNA promoter, such that once bound (in vitro), UAF does not readily exchange onto a competing template. Of the polypeptides previously identified in purified UAF, three are encoded by genes required for Pol I transcription in vivo: RRN5, RRN9, and RRN10.

RRN11 encodes the third subunit of the complex containing Rrn6p and Rrn7p that is essential for the initiation of rDNA transcription by yeast RNA polymerase I.

A new gene, RRN11, has been defined by certain rrn mutants of Saccharomyces cerevisiae which are defective specifically in the transcription of 35 S rRNA gene by RNA polymerase I (pol I). We have cloned the gene and found that it encodes a protein of 507 amino acids. We have used a strain with the chromosomal RRN11 deleted and carrying HA1 epitope-tagged RRN11 on a plasmid to isolate a protein complex containing the protein encoded by RRN11.

Organization of the centromeric region of chromosome XIV in Saccharomyces cerevisiae.

A 15.1 kb fragment of the yeast genome was allocated to the centromeric region of chromosome XIV by genetic mapping. It contained six bona fide genes, RPC34, FUN34, CIT1 (Suissa et al.