A locus at 19p13 is associated with breast cancer (BC) and ovarian cancer (OC) risk. Here we analyse 438 SNPs in this region in 46,451 BC and 15,438 OC cases, 15,252 BRCA1 mutation carriers and 73,444 controls and identify 13 candidate causal SNPs associated with serous OC (P=9.2 x 10(-20)), ER-negative BC (P=1.1 x 10(-13)), BRCA1-associated BC (P=7.7 x 10(-16)) and triple negative BC (P-diff=2 x 10(-5)). Genotype-gene expression associations are identified for candidate target genes ANKLE1 (P=2 x 10(-3)) and ABHD8 (P<2 x 10(-3)). Chromosome conformation capture identifies interactions between four candidate SNPs and ABHD8, and luciferase assays indicate six risk alleles increased transactivation of the ADHD8 promoter. Targeted deletion of a region containing risk SNP rs56069439 in a putative enhancer induces ANKLE1 downregulation; and mRNA stability assays indicate functional effects for an ANKLE1 3'-UTR SNP. Altogether, these data suggest that multiple SNPs at 19p13 regulate ABHD8 and perhaps ANKLE1 expression, and indicate common mechanisms underlying breast and ovarian cancer risk.
        
Title: Bifunctional indole-3-acetyl transferase catalyses synthesis and hydrolysis of indole-3-acetyl-myo-inositol in immature endosperm of Zea mays Kowalczyk S, Jakubowska A, Zielieska E, Bandurski RS Ref: Physiologica Plantarum, 119:165, 2003 : PubMed
1-O-(indole-3-acetyl)-beta-d-glucose: myo-inositol indoleacetyl transferase (IA-myo-inositol synthase) is an important enzyme in IAA metabolism. This enzyme catalyses the transfer of the indole acetyl (IA) moiety from 1-O-(indole-3-acetyl)-beta-d-glucose to myo-inositol to form IA-myo-inositol and glucose. IA-myo-inositol synthase was purified to an electrophoretically homogenous state from maize liquid endosperm by fractionation with ammonium sulphate, anion-exchange, adsorption on hydroxylapatite, affinity chromatography on ConA-Sepharose, preparative PAGE and isoelectric focusing. We thus obtained two enzyme preparations which differ in their Rf on 8% polyacrylamide gel. The preparation of Rf 0.36 contained a single 56.4 kDa polypeptide, whereas the preparation of Rf 0.39 consisted of two polypeptides of 56.4 and 53.5 kDa. Both purified preparations of IAInos synthase also exhibited the activity of an IAInos hydrolase, showing that the dual activity was associated with a single protein. Results of gel filtration and analytical SDS-PAGE suggest that the native enzyme exists as both a monomeric (65 kDa) and homo- or heterodimeric form (110130 kDa). Analysis of peptide maps and amino acid sequences of two 21 amino-acid peptides showed that polypeptides of 56.4 and 53.5 kDa have the same primary structure and that the 3 kDa difference in molecular mass is probably caused by different glycosylation levels. Comparison of this partial and internal amino acid sequence with sequences of other plant acyltransferases indicated similarity to several proteins which belonged to the serine carboxypeptidase-like (SCPL) acyltransferase family.