Cell-type-specific splicing factors and the regulation of alternative RNA splicing.

A very wide variety of biological processes are regulated by alternative splicing. By this means, a gene can be transcribed in several different tissues but in each tissue the RNA transcript is spliced in a particular way to produce a different mRNA and hence a different protein. It is now clear that alternative splicing is regulated by factors which are expressed in a tissue-specific manner and which are necessary for the splicing events to occur. This review will discuss the evidence for the existence of these factors, their nature, and the mechanisms by which they regulate splicing by interacting with sequences in the RNA.