Amplified In Breast Cancer 1 (ABC1)

Analysis of the primary structure of the ABC1 protein uncovered two regions of this protein with a high likelihood of forming coiled-coils and assembly of a mouse ABC1 cDNA showed that this protein is conserved between mouse and man. ABC1 antisera showed that, like its transcript, breast tumor lines that harbor amplification of 20q13.2 display high levels of the ABC1 protein compared to normal human fibroblasts or a breast cancer line that does not overexpress the ABC1 mRNA. ABC1 mRNA exhibits a limited expression pattern in human tissue with high relative transcript levels observed only in brain and prostate. Immunofluorescence microscopy indicates ABC1 displays a punctate localization pattern in the cytoplasm of cultured cells, but biochemical fractionation indicates that this protein is not an integral component of membranous cytoplasmic organelles.