TY - JOUR
T1 - Interplay between human high mobility group protein 1 and replication protein A on psoralen-cross-linked DNA.
AU - Reddy, Madhava C
AU - Christensen, Jesper
AU - Vasquez, Karen M
N1 - Keywords: Base Sequence; Binding, Competitive; DNA; DNA Damage; DNA Repair; DNA Replication; DNA-Binding Proteins; HMGB1 Protein; Humans; Molecular Sequence Data; Nucleic Acid Conformation; Nucleic Acid Heteroduplexes; Oligonucleotides; Protein Binding; Replication Protein A; Trioxsalen; Ultraviolet Rays
PY - 2005
Y1 - 2005
N2 - Human high mobility group box (HMGB) 1 and -2 proteins are highly conserved and abundant chromosomal proteins that regulate chromatin structure and DNA metabolism. HMGB proteins bind preferentially to DNA that is bent or underwound and to DNA damaged by agents such as cisplatin, UVC radiation, and benzo[a]pyrenediol epoxide (BPDE). Binding of HMGB1 to DNA adducts is thought to inhibit nucleotide excision repair (NER), leading to cell death, but the biological roles of these proteins remain obscure. We have used psoralen-modified triplex-forming oligonucleotides (TFOs) to direct a psoralen-DNA interstrand cross-link (ICL) to a specific site to determine the effect of HMGB proteins on recognition of these lesions. Our results reveal that human HMGB1 (but not HMGB2) binds with high affinity and specificity to psoralen ICLs, and interacts with the essential NER protein, replication protein A (RPA), at these lesions. RPA, shown previously to bind tightly to these lesions, also binds in the presence of HMGB1, without displacing HMGB1. A discrete ternary complex is formed, containing HMGB1, RPA, and psoralen-damaged DNA. Thus, HMGB1 has the ability to recognize ICLs, can cooperate with RPA in doing so, and likely modulates their repair by the NER machinery. The abundance of HMGB1 suggests that it may play an important role in determining the sensitivity of cells to DNA damage under physiological, experimental, and therapeutic conditions.
AB - Human high mobility group box (HMGB) 1 and -2 proteins are highly conserved and abundant chromosomal proteins that regulate chromatin structure and DNA metabolism. HMGB proteins bind preferentially to DNA that is bent or underwound and to DNA damaged by agents such as cisplatin, UVC radiation, and benzo[a]pyrenediol epoxide (BPDE). Binding of HMGB1 to DNA adducts is thought to inhibit nucleotide excision repair (NER), leading to cell death, but the biological roles of these proteins remain obscure. We have used psoralen-modified triplex-forming oligonucleotides (TFOs) to direct a psoralen-DNA interstrand cross-link (ICL) to a specific site to determine the effect of HMGB proteins on recognition of these lesions. Our results reveal that human HMGB1 (but not HMGB2) binds with high affinity and specificity to psoralen ICLs, and interacts with the essential NER protein, replication protein A (RPA), at these lesions. RPA, shown previously to bind tightly to these lesions, also binds in the presence of HMGB1, without displacing HMGB1. A discrete ternary complex is formed, containing HMGB1, RPA, and psoralen-damaged DNA. Thus, HMGB1 has the ability to recognize ICLs, can cooperate with RPA in doing so, and likely modulates their repair by the NER machinery. The abundance of HMGB1 suggests that it may play an important role in determining the sensitivity of cells to DNA damage under physiological, experimental, and therapeutic conditions.
U2 - 10.1021/bi047902n
DO - 10.1021/bi047902n
M3 - Journal article
C2 - 15766246
SN - 0006-2960
VL - 44
SP - 4188
EP - 4195
JO - Biochemistry
JF - Biochemistry
IS - 11
ER -