This invention provides an optimized method for enhancing self-amplifying
RNA expression and an enhanced self-amplifying
RNA. Specifically, it provides an optimized method for enhancing self-amplifying
RNA expression, which involves
codon optimization. The optimized region is a specific region of the
alphavirus non-
structural protein sequence of the self-amplifying RNA, where the
alphavirus non-
structural protein is nsP1234. It also provides a method for preparing the enhanced self-amplifying RNA, an enhanced self-amplifying RNA, and a
plasmid. This application improves the expression efficiency of the self-amplifying RNA
target gene by designing and constructing codon
sequence optimization for certain regions of these non-structural proteins.