Retinoblastoma protein

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spinqualitylabelsall models PDB ID 1o9k Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image
1o9k, resolution 2.60Å ()
Related:	1pjm, 1n4m, 1h24, 1ad6, 1h25, 1gh6, 1gux, 2aze
Structural annotation: Resources: CATH : 1O9Ka00, 1O9Kb00, 1O9Kc00, 1O9Kd00, 1O9Ke00, 1O9Kf00, 1O9Kg00, 1O9Kh00 InterPro : Ipr002720, Ipr013763, Ipr002719, Ipr015030, Ipr015652, Ipr015634, Ipr003316, Ipr015633, Ipr011991 Pfam : PF01858, PF01857, PF08934 SCOP : d1o9ka_, d1o9kb_, d1o9kc_, d1o9kd_, d1o9ke_, d1o9kf_, d1o9kg_, d1o9kh_
Evolutionary conservation: Toggle Conservation Colors: Rows = identical sequences: Further Information: Caveats, Explanation, Complete Results at ConSurfDB
Resources:	FirstGlance, OCA, RCSB, PDBsum
Coordinates:	save as pdb, mmCIF, xml

Contents 1 Retinoblastoma Protein (pRB) 2 pRb/EF binding in the cell cycle 3 Inhibition/ Activation of pRB 4 Retinoblastoma, Tumors, and Cancer

Retinoblastoma Protein (pRB)

The is a tumor suppressor protein that prevents excessive cell growth. If not mutated, it is present in our cells and blocks the growth of dysfunctional cells between the G1 and S phase of the cell cycle before they can undergo DNA replication. pRB regulates the function of cyclin and cyclin dependent kinase complexes which are needed for the cell to proceed cell growth. Retinoblastoma protein is dependent on the transcription factor E2F, which is bound to pRB's active site when it is dephosphorylated. In viral cells, and tumorous cells pRB is dysfunctional or completely lost.

pRb/EF binding in the cell cycle

A cell must go through the cell cycle in order to grow, and replicate. Before the cell can replicate it has to pass through the many phases of the cell cycle (have a picture of the cell cycle). There’s the Go phase also known as the resting phase in which the cell can remain dormant forever. Then G1 phase in which cell growth takes place. Next is R-phase restriction point which determines if the cell is ready to move on to the S phase, which is when the cell’s DNA is replicated. It moves on to the G2 phase and finally the M-phase where it divides. The phases where pRB function is necessary are during the Go phase, and during the restriction point that determines the transition from the G1 phase to the S phase. During these phases, the cell is deciding whether it will move on to the S-phase where it will replicate its DNA. If the cell is not growing adequately, for example if its DNA is damaged, then the retinoblastoma protein will dephosphorylate and bind to the E2F transcription factor, this causes the inhibition of E2F and of cyclin CDK complexes. When pRB is phosphorylated, it no longer inhibits cell growth and the cell can continue developing.

Inhibition/ Activation of pRB

Retinoblastoma, Tumors, and Cancer