Structural and functional contributions to the G1 blocking action of the retinoblastoma protein. (the 1992 Gordon Hamilton Fairley Memorial Lecture).

The retinoblastoma gene product (RB) contributes to normal cell growth control. One of its functions is manifest as a block to exit from G1, which is carried out by an RB subspecies which is un- or underphosphorylated. After RB phosphorylation, a process which occurs towards the end of G1 in cycling cells, the block is lifted allowing a cell to enter S. Here, we review a series of results which speak to the elements of RB structure which contribute to this activity. Included is its internal colinear protein receptor domain (i.e. the 'pocket').