CREB3L2
Function
Transcription factor involved in unfolded protein response (UPR). In the absence of endoplasmic reticulum (ER) stress, inserted into ER membranes, with N-terminal DNA-binding and transcription activation domains oriented toward the cytosolic face of the membrane. In response to ER stress, transported to the Golgi, where it is cleaved in a site-specific manner by resident proteases S1P/MBTPS1 and S2P/MBTPS2. The released N-terminal cytosolic domain is translocated to the nucleus to effect transcription of specific target genes. Plays a critical role in chondrogenesis by activating the transcription of SEC23A, which promotes the transport and secretion of cartilage matrix proteins, and possibly that of ER biogenesis-related genes (By similarity). In a neuroblastoma cell line, protects cells from ER stress-induced death (PubMed:17178827). In vitro activates transcription of target genes via direct binding to the CRE site (PubMed:17178827).
Involvement in disease
A chromosomal aberration involving CREB3L2 is found in low grade fibromyxoid sarcoma (LGFMS). Translocation t(7;16)(q33;p11) with FUS.
Post-translational modifications
Upon ER stress, translocated to the Golgi apparatus, where it is processed by regulated intramembrane proteolysis (RIP) to release the cytosol-facing N-terminal transcription factor domain. The cleavage is performed sequentially by site-1 and site-2 proteases (S1P/MBTPS1 and S2P/MBTPS2).
N-glycosylated.
Ubiquitinated by HRD1/SYVN1; undergoes 'Lys-48'-linked ubiquitination, followed by rapid proteasomal degradation under normal conditions. Upon ER stress, SYVN1 E3 ubiquitin-protein ligase dissociates from its substrate, ubiquitination does not occur and CREB3L2 is stabilized.
Sequence Similarities
Belongs to the bZIP family. ATF subfamily.
Tissue Specificity
Widely expressed with highest levels in placenta, lung, spleen and intestine, and lowest levels in heart, brain, skeletal muscle, thymus, colon and leukocytes. In fetal tissues, the weakest expression is detected in brain and heart.
Cellular localization
- Endoplasmic reticulum membrane
- Single-pass type II membrane protein
- ER membrane resident protein. Upon ER stress, translocated to the Golgi apparatus where it is cleaved. The cytosolic N-terminal fragment (processed cyclic AMP-responsive element-binding protein 3-like protein 1) is transported into the nucleus.
- Processed cyclic AMP-responsive element-binding protein 3-like protein 2
- Nucleus
- Upon ER stress, translocated into the nucleus.
Alternative names
BBF2H7, CREB3L2, Cyclic AMP-responsive element-binding protein 3-like protein 2, cAMP-responsive element-binding protein 3-like protein 2, BBF2 human homolog on chromosome 7