Also referred to as CBX3, the chromobox protein homolog 3 is an important protein. At the nuclear envelope of this protein, the nuclear heterochromatin and lamina are adjacent to the inner nuclear membrane. The protein is a component of heterochromatin and it is encoded by the gene that is responsible for binding DNA.
The protein is also able to bind what is known as the lamin B receptor, which is a membrane protein that is integral and is located in the inner nuclear membrane.
The association of heterochromatin in the inner nuclear membrane can be explained by the dual binding functions of the encoded protein.
Through H3 'Lys-9' trimethylation, it will contribute to local chromatin conversion to a heterochromatin-like repressive condition. It also mediates recruiting of the methyltransferases SUV39H1 and/or SUV39H2 via the PER complex to the E-box components of the circadian objective genes such as PER1 or PER2.
There are a number of different interactions for chromobox protein homolog 3. The protein has been shown to interact with the likes of CBX1, CBX5, Lamin B receptor, Ki-67, and PIM1.
The chromobox protein homolog 3 is also involved in forming functional kinetochore via interacting with MIS12 complex proteins.