RNA editing: cytidine to uridine conversion in apolipoprotein B mRNA

RNA editing is a post-transcriptional process that changes the informationa l capacity within the RNA. These processes include alterations made by nucl eotide deletion, insertion and base conversion. A to I and C to U conversio n occurs in mammals and these editing events are catalysed by RNA. binding deaminases. C to U editing of apoB mRNA was the first mammalian editing eve nt to be identified. The minimal protein complex necessary for apoB mRNA ed iting has been determined and consists of APOBEC-1 and ACF. Overexpression of APOBEC-1 in transgenic animals caused liver dysplasia and APOBEC-I has b een identified in neurofibromatosis type I tumours, suggesting that RNA edi ting may be another mechanism for tumourigenesis. several APOBEC-1-like pro teins have been identified, including a family of APOBEC-1-related proteins with unknown function on chromosome 22. This review summarises the differe nt types of RNA editing and discusses the current status of C to U apoB mRN A editing. This knowledge is very important in understanding the structure and function of these related proteins and their role in biology. (C) 2000 Elsevier Science B.V. All rights reserved.