Temperature controls nuclear import of Tam3 transposase inAntirrhinum

The temperature-dependent change in methylation of the Antirrhinum transposon Tam3 is controlled by the activity of its transposase.

The Antirrhinum majus transposon Tam3 undergoes low temperature-dependent transposition (LTDT). Growth at 15 degrees C permits transposition, whereas growth at 25 degrees C strongly suppresses it. The degree of Tam3 DNA methylation is altered somatically and positively correlated with growth temperature, an exceptional epigenetic system in plants. Using a Tam3-inactive line, we show that methyl...

Bipartite Nuclear Localization Signal Controls Nuclear Import and DNA-Binding Activity of IFN Regulatory Factor 3.

Accurate cellular localization plays a crucial role in the effective function of most signaling proteins, and nuclear trafficking is central to the function of transcription factors. IFN regulatory factor (IRF)3 is a master transcription factor responsible for the induction of type I IFN, which plays a crucial role in host antiviral innate immune responses. However, the mechanisms for control a...

Activity of IFN Regulatory Factor 3 Controls Nuclear Import and DNA - Binding Bipartite Nuclear Localization Signal

In vitro nuclear import

T he nuclear pore serves as the gateway to the nucleus, allowing molecules to slip in and out. A technique devised by Larry Gerace (Scripps Research Institute in La Jolla, California) and colleagues helped researchers ferret out the biochemical details of nuclear import and export, identifying the driving force as the protein Ran. The same system helped scientists pinpoint the proteins that fer...

Nuclear Import of Yeast Proteasomes

Proteasomes are highly conserved protease complexes responsible for the degradation of aberrant and short-lived proteins. In highly proliferating yeast and mammalian cells, proteasomes are predominantly nuclear. During quiescence and cell cycle arrest, proteasomes accumulate in granules in close proximity to the nuclear envelope/ER. With prolonged quiescence in yeast, these proteasome granules ...