RAD50 interactor 1 (RINT1)

RAD50 interactor 1 (RINT1) is an 87-kDa protein that serves multiple critical cellular functions through its interactions with various protein complexes[1]. Originally identified as a novel protein that interacts with the DNA repair protein RAD50, RINT1 contains several distinct structural domains including an N-terminal coiled-coil domain within the first 150 amino acids, a conserved central domain of approximately 350 amino acids, and a C-terminal region of 90 amino acids[1]. RINT1 exhibits sequence homology with proteins found in Drosophila melanogaster, particularly in its conserved central and C-terminal regions, which are essential for its interaction with RAD50[1]. The protein demonstrates cell cycle-dependent binding specificity, interacting with RAD50 specifically during late S and G2/M phases of the cell cycle, suggesting its involvement in cell cycle regulation[1]. Beyond its interaction with RAD50, RINT1 functions as a component of the ZW10 complex, which includes ZW10 and NAG proteins. This complex plays a pivotal role in retrograde transport from the Golgi apparatus to the endoplasmic reticulum (ER), working in association with ER SNAREs including Syntaxin 18, p31, and Sec22b[3]. The integrity of this complex is regulated by the autophagy factor UVRAG, which interacts with RINT1, demonstrating the intersection between Golgi-ER trafficking and autophagic mechanisms[3]. **DNA Damage Response and Cell Cycle Control:** RINT1 participates in radiation-induced G2/M checkpoint control[1]. Cells expressing N-terminally truncated RINT1 proteins display defective radiation-induced G2/M checkpoint responses, indicating its crucial role in DNA damage response pathways[1]. The protein is essential for telomere length control and has been shown to inhibit telomerase-independent telomere lengthening through its mediation of interactions between RAD50 and the pocket protein family member p130[7]. **Membrane Trafficking:** RINT1 is involved in regulating membrane traffic between the Golgi apparatus and the ER[5]. Its function in this capacity depends on its association within the NRZ complex, which is believed to play a role in SNARE assembly at the ER[5]. Disruption of RINT1 function leads to significant reduction in vesicle movement from the ER to the Golgi apparatus[7]. **Genomic Stability:** RINT1 inactivation triggers genomic instability, manifesting as chromosome fusion in dividing cells[3]. This genomic instability is accompanied by disruption of ER and Cis/Trans Golgi homeostasis in neurons, followed by increased ER stress[3]. **Developmental Biology:** RINT1 is essential for normal development, particularly in the central nervous system. Inactivation of RINT1 in neuroprogenitors leads to death at birth, highlighting its crucial role during embryonic development[3]. The protein is necessary during early mouse development, and its deficiency leads to severe developmental defects and neurodegeneration[3]. **Disease Associations:** RINT1 deficiency is associated with several pathological conditions including infantile liver failure syndrome 3 and acute liver failure[5]. Mutations in the RINT1 gene may be associated with breast cancer in human patients[5]. The protein's dysfunction is linked to ER stress, defective autophagy, and genomic instability in the central nervous system[3]. **Viral Interactions:** RINT1 has been identified as an interaction partner of human papillomavirus 16 (HPV16) E2 protein. This interaction disrupts the normal RINT1-ZW10 association and results in nuclear accumulation of RINT1, which appears to facilitate viral genome replication[7]. The recruitment of RINT1 to E2 nuclear foci may also result in recruitment of DNA damage-sensing protein complexes, suggesting a role in viral replication strategies[7]. While RINT1 itself has not been established as a direct therapeutic target with specific drugs, its essential roles in DNA repair, cell cycle control, and membrane trafficking make it an important protein for understanding cellular homeostasis and disease mechanisms. The protein's involvement in genomic stability maintenance and its interactions with both cellular DNA repair machinery and viral proteins suggest potential indirect therapeutic relevance in cancer treatment and antiviral strategies.

Other names

RAD50-interacting protein 1RINT-1HsRINT-1FLJ11785ILFS3

Not applicable (no direct targeting drugs identified)