nucleosomes Grb2 polyadenylation snk pleft Natsuyasumi LEVELS Gurken MAPK SECIS PTPs Flavivirus STAT1 riboswitch kappaB Calreticulin RNA SIGCHLD gp130 GroES SL4 transducing operon nucleoporins arginines APRZ chromatin structure proctolin AMPARs synaptonemal Chondroitin ubiquitinated modulating calpains