Barrier-to-autointegration factor (BAF or BANF1) is an abundant, highly conserved, small and essential protein that binds to dsDNA, chromatin, nuclear lamina proteins, histones and various transcription factors.
It was discovered as a cellular component of retrovirus pre-integration complex that inhibits their autointegration in vitro.
BANF1 is also required for many cellular functions, including the higher-order organization of chromatin and the transcription of specific genes. Recent findings suggest further roles for BANF1, including nuclear envelope assembly, regulating specific developmental processes and regulating retrovirus infectivity.
At least some of these roles are controlled by phosphorylation of the BAF N-terminus by the vaccinia-related kinase.
References
Margalit A, Brachner A, Gotzmann J, Foisner R, Gruenbaum Y. Barrier-to-autointegration factor - a BAFfling little protein. Trends Cell Biol. 2007 Feb 20; PMID: 17320395