Rbp1, or Retinol-binding protein type 1, is an intracellular chaperone. It binds retinol and retinal with high affinity, protects retinoids from non-specific oxidation, and is involved in delivering retinoids to specific enzymes for the biosynthesis of all-trans retinoic acid (atRA). It also plays roles in multiple biological processes such as lipid metabolism in Drosophila [4], transcriptional regulation in mammalian cells [5,7,8], and osteoblastic differentiation in mice [6].

In mammary epithelial cells and tissues, reduced Rbp1 expression is associated with decreased atRA levels, which in turn impacts cell proliferation and collagen deposition [1]. In oral squamous cell carcinoma (OSCC), Rbp1 overexpression promotes cell growth, migration, invasion, and activates oncogenic autophagy via the RBP1-CKAP4 axis [2]. In coronary artery disease (CAD) and multiple cancers, Rbp1 is hypermethylated, and its expression is related to poor prognosis and immune infiltration [3].

In summary, Rbp1 is crucial for retinoid-related functions, cell proliferation regulation, and has implications in various disease conditions including cancer and CAD. Studies on Rbp1 contribute to understanding disease mechanisms and may potentially lead to new therapeutic strategies for these diseases.

References:

1. Yu, Jianshi, Perri, Mariarita, Jones, Jace W, Cione, Erika, Kane, Maureen A. 2022. Altered RBP1 Gene Expression Impacts Epithelial Cell Retinoic Acid, Proliferation, and Microenvironment. In Cells, 11, . doi:10.3390/cells11050792. https://pubmed.ncbi.nlm.nih.gov/35269414/

2. Gao, Ling, Wang, Qibo, Ren, Wenhao, Liang, Xiao, Zhi, Keqian. 2020. The RBP1-CKAP4 axis activates oncogenic autophagy and promotes cancer progression in oral squamous cell carcinoma. In Cell death & disease, 11, 488. doi:10.1038/s41419-020-2693-8. https://pubmed.ncbi.nlm.nih.gov/32587255/

3. Wang, Yumian, Zhang, Li, Chen, Han, Cui, Yun, Wang, Hong. 2023. Coronary artery disease-associated immune gene RBP1 and its pan-cancer analysis. In Frontiers in cardiovascular medicine, 10, 1091950. doi:10.3389/fcvm.2023.1091950. https://pubmed.ncbi.nlm.nih.gov/36970364/

4. Bennick, Ryan A, Nagengast, Alexis A, DiAngelo, Justin R. 2019. The SR proteins SF2 and RBP1 regulate triglyceride storage in the fat body of Drosophila. In Biochemical and biophysical research communications, 516, 928-933. doi:10.1016/j.bbrc.2019.06.151. https://pubmed.ncbi.nlm.nih.gov/31277943/

5. Binda, Olivier, Roy, Jean-Sébastien, Branton, Philip E. . RBP1 family proteins exhibit SUMOylation-dependent transcriptional repression and induce cell growth inhibition reminiscent of senescence. In Molecular and cellular biology, 26, 1917-31. doi:. https://pubmed.ncbi.nlm.nih.gov/16479010/

6. Monroe, David G, Hawse, John R, Subramaniam, Malayannan, Spelsberg, Thomas C. 2010. Retinoblastoma binding protein-1 (RBP1) is a Runx2 coactivator and promotes osteoblastic differentiation. In BMC musculoskeletal disorders, 11, 104. doi:10.1186/1471-2474-11-104. https://pubmed.ncbi.nlm.nih.gov/20509905/

7. Lai, A, Marcellus, R C, Corbeil, H B, Branton, P E. . RBP1 induces growth arrest by repression of E2F-dependent transcription. In Oncogene, 18, 2091-100. doi:. https://pubmed.ncbi.nlm.nih.gov/10321733/

8. Lai, A, Lee, J M, Yang, W M, Seto, E, Branton, P E. . RBP1 recruits both histone deacetylase-dependent and -independent repression activities to retinoblastoma family proteins. In Molecular and cellular biology, 19, 6632-41. doi:. https://pubmed.ncbi.nlm.nih.gov/10490602/