·      In Alzheimer’s the APP protein is the main constituent of the amyloid plaque. The APP protein is processed into its mature form by two enzymes. Beta secretase followed by gamma secretase. Beta secretase is coded for by BACE1. 

·      It is believed that an antisense non-coding RNA is present on the opposite strand to where BACE1 is transcribed as is known as BACE1-AS. 

·      The function of BACE1-AS is thought to be one of amplifying the gene product. BACE1-AS stabilises the BACE1 mRNA upon transcription and allows for more efficient protein production. 

·      This is linked to Alzheimer’s pathology as a mutation in APP is thought to be linked to the formation of amyloid plaques. BACE1-AS can bind to the miRNA that is supposed to break down and regulate BACE1 expression  (miR-485-5p)meaning more BACE1 gene product is produced, so more beta-secretase which means more APP processing to form more amyloid plaque. 

·      This is an example of feedforward regulation 

·      It is also thought that the BACE1-AS  transcription can be upregulated by presence of aB-40/42 the amyloid plaque composed mainly of the BACE1 gene product