ASF1B
Description
The ASF1B (anti-silencing function 1B histone chaperone) is a protein-coding gene located on chromosome 19.
ASF1B is a protein encoded by the ASF1B gene in humans. It is a member of the H3/H4 family of histone chaperone proteins and is similar to the anti-silencing function-1 gene in yeast. ASF1B is a substrate of the tousled-like kinase family of cell cycle-regulated kinases and may play a key role in modulating the nucleosome structure of chromatin by ensuring a constant supply of histones at sites of nucleosome assembly. ASF1B interacts with TLK2, CHAF1B, TLK1, and CHAF1A.
ASF1B is a histone chaperone that plays a role in nucleosome assembly and disassembly by facilitating histone deposition, exchange, and removal. It works with the chromatin assembly factor 1 (CAF-1) to promote replication-dependent chromatin assembly. ASF1B is also involved in the nuclear import of the histone H3-H4 dimer in conjunction with importin-4 (IPO4), specifically recognizing and binding newly synthesized histones that have undergone monomethylation of H3 'Lys-9' (H3K9me1) and diacetylation at 'Lys-5' and 'Lys-12' of H4 (H4K5K12ac) marks in the cytosol. However, ASF1B does not participate in replication-independent nucleosome deposition, which is instead mediated by ASF1A and HIRA. It is essential for gonad development.
ASF1B is also known as CIA-II.
Associated Diseases
- cancer
- immune deficiency, familial variable
- hyper-IgM syndrome type 3
- classic Hodgkin lymphoma
- IgE responsiveness, atopic
- hyper-IgM syndrome type 2
- hyper-IgM syndrome type 5
- immunodeficiency, common variable, 14
- severe combined immunodeficiency due to CARD11 deficiency
