Table 3. Effects of mutations in the LxCxE motif of cellular proteins on their function and interaction with pRB.

pRB binding protein	LxCxE mutation	Effect on binding to pRB	Effect on function	References
RBP-1	E to K	Retains binding to pRB	ND	[109]
HBP-1	C to G in both LxCxE and LxCxE	No binding to pRB	Loss of transcriptional repression by HBPl	[170]
CtIP	Deletion	No binding to pRB	ND	[171]
HDAC-1	Deletion	No binding to pRB	Inhibition of pRB repressive function	[172,173]
BRG-1	Mutation in pRB LxCxE cleft	Retains binding to pRB	ND	[86]
EID-1	Deletion	No binding to pRB	No effect	[174]
Gankyrin	E to A	No binding to pRB	Inhibition of phosphorylation and degradation of pRB	[110]
RFC-1	C to G, E to K	No binding to pRB	Loss of RFC function in promoting cell survival after DNA damage	[175]
BRCA-1	RXRXH	Retains binding to pRB	Altered tumour suppressor activity of BRCA1	[111,172]
ASK-1	LKCFE to VRCFD	No binding to pRB	Altered ASK-1 activity in induction of apoptosis	[106]
Cyclin D1, D2	C to G, E to K	Profoundly diminished binding to pRB	Partial abrogation of pRB-induced growth arrest and senescence	[107,176]
RBBP-9	L to Q	No binding to pRB	ND	[177]
NuMA	C to G, E to K	No binding to pRB	Abnormal organization of spindle microtubules	[178]