Homeobox containing 1, also known as homeobox telomere-binding protein 1 (HOT1), is a
protein that in humans is encoded by the HMBOX1 gene.[5] HMBOX1 directly binds to the double-stranded repeat sequence of
telomeres.[6][7]
HMBOX1 has originally been identified to associate with telomeric chromatin in telomerase-positive cancer cells and cancer cells that maintain their telomeres based on the
Alternative Lengthening of Telomeres (ALT) mechanism by the 'reverse
ChIP' technique PICh (Proteomics of Isolated Chromatin segments).[6] Subsequently, direct binding to telomeric DNA was demonstrated through a co-
crystal structure of the
DNA-binding domain of HMBOX1 with telomeric DNA.[7] Loss-of-function and gain-of-function experiments classify HMBOX1 as a positive regulator of telomere length.[7][8] HMBOX1 had originally been described as a transcriptional repressor based on
reporter gene assays,[9] but genome-wide approaches using
RNA-seq and
ChIP-seq see little to no such effect at least in several cancer cell lines.[10]
^Chen S, Saiyin H, Zeng X, Xi J, Liu X, Li X, Yu L (2006). "Isolation and functional analysis of human HMBOX1, a homeobox containing protein with transcriptional repressor activity". Cytogenetic and Genome Research. 114 (2): 131–6.
doi:
10.1159/000093328.
PMID16825764.
S2CID21067536.
Homeobox containing 1, also known as homeobox telomere-binding protein 1 (HOT1), is a
protein that in humans is encoded by the HMBOX1 gene.[5] HMBOX1 directly binds to the double-stranded repeat sequence of
telomeres.[6][7]
HMBOX1 has originally been identified to associate with telomeric chromatin in telomerase-positive cancer cells and cancer cells that maintain their telomeres based on the
Alternative Lengthening of Telomeres (ALT) mechanism by the 'reverse
ChIP' technique PICh (Proteomics of Isolated Chromatin segments).[6] Subsequently, direct binding to telomeric DNA was demonstrated through a co-
crystal structure of the
DNA-binding domain of HMBOX1 with telomeric DNA.[7] Loss-of-function and gain-of-function experiments classify HMBOX1 as a positive regulator of telomere length.[7][8] HMBOX1 had originally been described as a transcriptional repressor based on
reporter gene assays,[9] but genome-wide approaches using
RNA-seq and
ChIP-seq see little to no such effect at least in several cancer cell lines.[10]
^Chen S, Saiyin H, Zeng X, Xi J, Liu X, Li X, Yu L (2006). "Isolation and functional analysis of human HMBOX1, a homeobox containing protein with transcriptional repressor activity". Cytogenetic and Genome Research. 114 (2): 131–6.
doi:
10.1159/000093328.
PMID16825764.
S2CID21067536.