Anti-silencing function 1 (Asf1) is a conserved key eukaryotic histone H3/H4 
chaperone that participates in a variety of DNA and chromatin-related processes. 
These include the assembly and disassembly of histones H3 and H4 from chromatin 
during replication, transcription, and DNA repair. In addition, Asf1 is required 
for H3K56 acetylation activity dependent on histone acetyltransferase Rtt109. 
Thus, Asf1 impacts on many aspects of DNA metabolism. To gain insights into the 
functional links of Asf1 with other cellular machineries, we employed mass 
spectrometry coupled to tandem affinity purification (TAP) to investigate novel 
physical interactions of Asf1. Under different TAP-MS analysis conditions, we 
describe a new repertoire of Asf1 physical interactions and novel Asf1 
post-translational modifications as ubiquitination, methylation and acetylation 
that open up new ways to regulate Asf1 functions. Asf1 co-purifies with several 
subunits of the TREX-2, SAGA complexes, and with nucleoporins Nup2, Nup60, and 
Nup57, which are all involved in transcription coupled to mRNA export in 
eukaryotes. Reciprocally, Thp1 and Sus1 interact with Asf1. Albeit mRNA export 
and GAL1 transcription are not affected in asf1Δ a strong genetic interaction 
exists between ASF1 and SUS1. Notably, supporting a functional link between Asf1 
and TREX-2, both Sus1 and Thp1 affect the levels of Asf1-dependent histone H3K56 
acetylation and histone H3 and H4 incorporation onto chromatin. Additionally, we 
provide evidence for a role of Asf1 in histone H2B ubiquitination. This work 
proposes a functional link between Asf1 and TREX-2 components in histone 
metabolism at the vicinity of the nuclear pore complex.