This small domain is found at the N-terminal end in human SAM and SH3 domain-containing protein 1 (SASH1) and NEDD8 ultimate buster 1(NUB1) and similar animal proteins. The function of this domain is unknown, however it shows some structural similarity to the homeodomain suggesting a potential DNA-binding function.SASH1 is a positive regulator of NF-kappa-B signalling downstream of TLR4 activation. It acts as a scaffold molecule to assemble a molecular complex that includes TRAF6, MAP3K7, CHUK and IKBKB []. It is involved in the regulation of cell mobility [, , ]and regulates lipolysaccharide (LPS)-induced endothelial cell migration [].NUB1 is an specific down-regulator of the NEDD8 conjugation system. It recruits NEDD8, UBD, and their conjugates to the proteasome for degradation [].
