Cellular retinoic acid-binding protein 1 (CRABP1)

Cellular retinoic acid-binding protein 1 (CRABP1) is a highly conserved and ubiquitously expressed intracellular protein responsible for binding, sequestering, and transporting retinoic acid—a key metabolite of vitamin A—within the cell[1][2][4]. CRABP1 plays a fundamental role in regulating the availability of retinoic acid for both genomic actions (by influencing its access to nuclear retinoic acid receptors and thus modulating gene expression), and for rapid, non-genomic signaling through interactions with cytosolic effectors such as CaMKII and ERK1/2[1][2]. It is structurally related to other intracellular lipid-binding proteins and features a characteristic beta-barrel structure. CRABP1 is essential in modulating cell proliferation, differentiation, and apoptosis, and is implicated in several physiological and pathological processes, notably in neural stem cell biology, cancer proliferation, and breast cancer associated with pregnancy. It is considered a therapeutic target due to its role in modulating retinoic acid's functions in key cellular pathways, although direct drug targeting and biomarker applications are still emergent fields of research[1][2][4].

Other names

CRABP1cellular retinoic acid binding protein type 1

Ligand binding: sequesters and transports retinoic acid to appropriate intracellular destinations; Modulates retinoic acid bioavailability for nuclear retinoic acid receptors, impacting gene expression; Mediates non-canonical (non-genomic) signaling by directly interacting with cytosolic proteins such as CaMKII and ERK1/2; Induces or inhibits apoptosis and cell proliferation depending on context (e.g., tumor suppressive in some cells)