HMBOX1

Binds directly to 5'-TTAGGG-3' repeats in telomeric DNA. Associates with the telomerase complex at sites of active telomere processing and positively regulates telomere elongation. Important for TERT binding to chromatin, indicating a role in recruitment of the telomerase complex to telomeres (By similarity). Also plays a role in the alternative lengthening of telomeres (ALT) pathway in telomerase-negative cells where it promotes formation and/or maintenance of ALT-associated promyelocytic leukemia bodies (APBs). Enhances formation of telomere C-circles in ALT cells, suggesting a possible role in telomere recombination. Might also be involved in the DNA damage response at telomeres..

Function from UniProtKB (Q6NT76), read 2026-09-23. CC BY 4.0.