About RANBP / RAN Binding Protein:
The RAN binding protein is an enzyme. It is present in humans, where it is encoded by the RANBP1 gene. The RANBP will interact exclusively with GTP-charged Ran. It encodes the 23-kD protein, which binds to RAn complexed -- not with GDP, but with GTP. It will not activate the GTPase activity of RAN. However, it will have a big impact on GTP hydrolysis by the RANGTPase-activating protein. Furthermore, the RANBP1 cDNA will encode a 201-amino acid protein if it is 92% similar to its mouse homolog. The RANBP1 will act as a negative regulator of RCC1 by inhibiting RCC!-stimulate guanine nucleotide release from RAN. It will bind to two different types of effector that you’ll find within the cell. The RAN-binding proteins play a role in ending export processes from the nucleus to the cytoplasm. Researchers have also found that they have importin-beta-like molecules -- these help to bind cargo proteins during nuclear transport.
You’ll find the ran-binding domain, which is a conserved sequence motif, in several proteins that are involved in the transport processes. RanBP2 contains four domains, which means it is responsible for a significant portion of the cytoplasmic fibrils, which come from the nuclear-pore complex. In terms of structure, the ran bound to a non-hydrolysable GTP analogue in complex with the first ran-binding domain -- in the human RanBP2 -- shows that the RanBD1 has a pleckstrin-homology domain fold. It has also been shown that the switch-I region of Ran x GppNHp is similar to the canonical Ras GppNHp structure.