CREB3L2 (cAMP responsive element binding protein 3-like 2)

519 amino acids, 57 kDa. The amino acid sequence spanning residues 291-356 of the predicted human CREB3L2 protein contains a consensus B-ZIP domain highly similar to that in the CREB3L1, CREB3L3, CREB3L4, CREB3 and Drosophila Bbf-2 transcription factors with 80, 60, 59, 56 and 71% identity, respectively. It also contains the amino acid sequence RRKKKEY which is exactly conserved among CREB, CREM, ATF1, ATF6 and CREBL1. The leucine zipper motif of CREB3L2 is similar to that in CREB3L3 and CREB3L4 (pattern L-X6-C-X6-L-X6-L-X6-L-X6-L). It contains six repeats and consists of five leucines and one cysteine at the second heptad position (amino acid 328) of the leucine zipper. Downstream of the B-ZIP domain, CREB3L2 also contains a hydrophobic region, which was predicted to be an a-helical transmembrane domain (position 376-397; GTCLMVVVLCFAVAFGSFFQGY) by the prediction program PSORT II. This structural feature is also seen in the other members of the family, i.e. CREB3L1, CREB3L3, CREB3 and CREB3L4.