Classification of novel RNA binding proteins. Novel RBPs can be classified in two main groups: Autonomous binders such as EB1, Tm1, TRIM-NHL, and at least some TRIM-SPRY proteins which bind RNA directly. The recurring validation of their RNA binding properties in individual studies changes their status from being a novel RBP to being a classical, general RBP. Others, like Thioredoxin (TXN), SNTB1, or FKBP12, however, can bind RNA only dependent on other factors present in vivo. It cannot be dismissed at the moment that they might not bind RNA altogether. And finally, it remains to be confirmed if proteins like EB1 which bind RNA in vitro do so in a functional relevant way in vivo.
