Final answer:
Cis- or trans-splicing of a protein occurs between transcription and translation, involving the processing of RNA to remove introns and splice exons together to form mature mRNA before it is translated into protein in the cytoplasm.
Step-by-step explanation:
When a protein is synthesized, cis- or trans-splicing of that protein occurs between transcription and translation. RNA transcription, which takes place in the nucleus, occurs prior to protein formation. After transcription, the RNA must be processed to create a mature mRNA. This processing includes the addition of a 5' cap and poly-A tail, as well as the excision of introns and the splicing of exons. The spliceosomes play a crucial role in this process by binding to the signals at the exon-intron borders to remove the introns and ligate the exons together. Once spliced, the mRNA is mature and can be transported out of the nucleus to the cytoplasm for translation into protein