Topoisomerase IIbeta activates a subset of neuronal genes that are repressed in AT-rich genomic environment.

DNA topoisomerase II (topo II) catalyzes a strand passage reaction in that one duplex is passed through a transient brake or gate in another. Completion of late stages of neuronal development depends on the presence of active beta isoform (topo IIbeta). The enzyme appears to aid the transcriptional induction of a limited number of genes essential for neuronal maturation.

Histone acetylation-independent transcription stimulation by a histone chaperone.

Histone chaperones are thought to be important for maintaining the physiological activity of histones; however, their exact roles are not fully understood. The physiological function of template activating factor (TAF)-I, one of the histone chaperones, also remains unclear; however, its biochemical properties have been well studied. By performing microarray analyses, we found that TAF-I stimulates the transcription of a sub-set of genes.

Synergistic action of MLL, a TRX protein with template activating factor-I, a histone chaperone.

MLL is involved in the process of gene activity maintenance. It is shown that the amino-terminal region of MLL (MLLN) interacts with TAF-Ibeta/SET. In this study, using yeast two-hybrid assays, we have found that the acidic region of TAF-Ibeta is essential for its binding to MLLN.

Aberrant intracellular localization of SET-CAN fusion protein, associated with a leukemia, disorganizes nuclear export.

The SET-CAN fusion gene is the product of a chromosomal rearrangement found on 9q34 associated with an acute undifferentiated leukemia. SET-CAN encodes an almost complete SET protein fused to the C-terminal two-thirds of CAN. SET is also known as TAF-Ibeta, a histone chaperone and intracellular inhibitor of protein phosphatase 2A, whereas CAN is identical to Nup214, a nucleoporin protein.

Involvement of nucleocytoplasmic shuttling of yeast Nap1 in mitotic progression.

Nucleosome assembly protein 1 (Nap1) is widely conserved from yeasts to humans and facilitates nucleosome formation in vitro as a histone chaperone. Nap1 is generally localized in the cytoplasm, except that subcellular localization of Drosophila melanogaster Nap1 is dynamically regulated between the cytoplasm and nucleus during early development. The cytoplasmic localization of Nap1 is seemingly incompatible with the proposed role of Nap1 in nucleosome formation, which should occur in the nucleus.