Identify text pattern in R dataframe

I have identifiers in two columns of a dataframe but with different structure. It looks like this:

  Description1                Description2
1  A0A2H1CVW1_FASHEprotein1   tr|A0A2H1CVW1|A0A2H1CVW1_FASHEprotein1 
2  A0A4E0RAA2_FASHEprotein2   tr|A0A2H1BSG1|A0A2H1BSG1_FASHEprotein3
3  A0A2H1CFJ4_FASHEprotein4   tr|A0A2H1CFJ4|A0A2H1CFJ4_FASHEprotein4

How could I identify the different identifiers between the two column, for example in row 2?