Role of protein kinase CK2 in antitumor drug resistance

Table 1 Major drug resistance-related proteins which have been reported as regulated by CK2 (via direct phosphorylation and/or control of the protein amount)

Protein	Function	Phospho-site	Phosphoryl. by CK2	Protein level controlled by CK2	REF
ABCG2	MDR efflux pump			Yes	[15]
AKT (PKB)	Ser/Thr kinase	Ser129	Yes		[16,17,18]
ARC	Apoptosis repressor	Thr149	Yes		[19]
BRD4	Epigenetic regulator and transcription cofactor		Yes		[20]
CDC37	Co-chaperone protein	Ser13	Yes	Yes	[21]
EGFR	Receptor tyrosine kinase			Yes	[22]
FLIP	Inhibitor of apoptosis			Yes	[23]
GLI2	Transcription factor			Yes	[24]
HMGA1	DNA replication, transcription, heterochromatin organization		Yes		[25]
HSP27	Chaperone protein			Yes	[26, 27]
HSP70	Chaperone protein			Yes	[26]
HSP90	Chaperone protein	Thr22 Ser225 Ser254	Yes		[28, 29]
IKBα	NF-κB inhibitor	Ser32 Ser36	Yes		[30]
MDC1	DNA repair (DSB)		Yes		[31]
MRE11	DNA repair (DSB)		Yes	Yes	[32]
MRP1	MDR efflux pump	Thr249	Yes		[33]
NF-κB p65(RelA)	Transcription factor	Ser259	Yes		[22, 30, 34,35,36]
p53	Tumor suppressor	Ser392	Yes	Yes	[37,38,39]
P-gp	MDR efflux pump	Ser665 Ser669 Ser681	Yes	Yes	[28, 40]
PTEN	Lipid phosphatase	Ser370, Ser380, Thr382, Thr383, Ser385 (*)	Yes	Yes	[41,42,43]
STAT3	Transcription factor	Ser727	Yes		[36]
Survivin	Inhibitor of apoptosis			Yes	[44]
TAp73	Tumor suppressor	Thr27	Yes	Yes	[45]
Topoisomerase I	DNA structure and function regulation	Ser506	Yes		[46,47,48]
Topoisomerase II	DNA structure and function regulation	Ser1106	Yes		[49,50,51,52]
XRCC1	DNA repair (SSB)	S485/T488 and S518/T519/T523	Yes		[53,54,55]
XRCC4	DNA repair (DSB, NHEJ)	Thr233	Yes		[56]

The quotations refer to the publications reporting a CK2-dependent regulation of these proteins in a drug resistance context. (*) Sites are reported in ref. [57]

ISSN: 1756-9966