Hi Gunnar,

I have tested P2a, T2A and E2A in constructs meant for expression in nurons and in my hands T2A ended up being the most effective signal. Nevertheless, how effective the signal is depends in its recognition and interaction by the proteases. If the sequence is surrounded by strong 2ry-3ry structures its cleavage might decrease significantly. Consider a sequential P2a-T2a signal (See study below), it may help bypass stearic effects and give your binary proteins higher cleavage efficiency.

Please check this work: https://www.nature.com/articles/s41598-017-02460-2

Cheers,