RAD50 Interacting Protein 1 (RINT1)

The deduced 792-amino acid protein has several leucine heptad repeats that form an N-terminal coiled-coil region. Western blot analysis of human cell lines detected an 87-kD RINT1 doublet. Further experiments suggested that the higher molecular mass protein may be translated from an upstream non-AUG start codon.

RINT1 bound RAD50 only during late S and G2/M phases, and human breast cancer cells expressing an N-terminally truncated RINT1 protein displayed defective radiation-induced G2/M checkpoint. the second leucine heptad repeat of RAD50 and amino acids 257 to 792 of RINT1 were required for RAD50-RINT1 interaction. RINT1 may play a role in cell cycle control after DNA damage.