Read with caution!
This post was written during early stages of trying to understand a complex scientific problem, and we didn't get everything right. The original author no longer endorses the content of this post. It is being left online for historical reasons, but read at your own risk.
I spent some time looking for the PRNP and trying to understand its mysteries. Even though PrP is 209 amino acids (253 pre-translation, which is what the codon numberings are based on), the PRNP gene clocks in at 15.36 kb. So when I first saw it, I wondered, what IS all that other stuff? Ensembl’s gene summary with its list of five “transcripts” didn’t help me that much. There are two 253-aa protein coding sequences listed, which both point to the same link, which I looked at a bit. It looks mostly right as a reference sequence– 127G, 178D, 219E– although it’s a bit weird in that it lists codon 129 as Y (Tyrosine), not a genotype I’ve ever heard of.
NCBI’s page on PRNP was a bit more helpful — it actually lists the different components of the PRNP gene with a bit of description of each. If you scroll down to CDS, that appears to be the one of interest since it is described as:
prion-related protein; major prion protein; CD230 antigen; prion protein PrP; prion protein (p27-30) (Creutzfeldt-Jakob disease, Gerstmann-Strausler-Scheinker syndrome, fatal familial insomnia)
And if you click the CDS link, it highlights the DNA sequence that generates PrP.
Question: so what are the other 15.36 kb? Is any of that other stuff transcribed or translated? Is there any alternative splicing or is PrP the one and only product of PRNP?