Rb encoded by the RB1 gene in humans, is expressed by retina and belongs to the etinoblastoma-associated protein family. The hole protein consists of 928 a.a. and the rHuRb fragment occupies sequence of 792-929 a.a.. Rb is a key regulator of entry into cell division that acts as a tumor suppressor. It has many functions, for example, promotes G0-G1 transition when phosphorylated by CDK3/cyclin-C, and acts as a transcription repressor of E2F1 target genes and so on. The rHuRb is the region that rich of modified residue like phosphothreonine and N6-acetyllysine.
Reference
1. Lee WH, Shew JY, Hong FD, et al. 1987. Nature, 329: 642-5
2. Lee WH, Bookstein R, Hong F, et al. 1987. Science, 235: 1394-9
3. Toguchida J, McGee TL, Paterson JC, et al. 1993. Genomics, 17: 535-43
4. Fattaey AR, Helin K, Dembski MS, et al. 1993. Oncogene, 8: 3149-56.