Related Experiment Video
Updated: Jan 30, 2026

Studying Copper Nanoparticle-Induced Programmed Cell Death in Bacteria
Published on: May 16, 2025
Ran1 is essential for parental macronuclear import of apoptosis-inducing factor and programmed nuclear death in
Haixia Liang1,2, Jing Xu1, Wei Wang1
1Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan, China.
Abstract:
During programmed nuclear death (PND), apoptosis-inducing factor (AIF) translocates from mitochondria to the parental macronucleus (MAC) in Tetrahymena thermophila. In the degenerating parental MAC, AIF induces chromatin condensation and large-scale DNA fragmentation in a caspase-independent manner. However, the regulation of AIF nuclear translocation and molecular mechanism of PND are less clear. In this study, we demonstrated that the asymmetric distribution of nuclear GDP-bound Ran1-mimetic mutant Ran1T25N and cytoplasmic GTP-bound Ran1-mimetic mutant Ran1Q70L exists across the parental macronuclear-cytoplasmic barrier during PND. Knockdown of RAN1 led to defects in PND progression and failure of parental macronuclear accumulation of AIF. Moreover, AIF parental macronuclear import occurred in Ran1T25N mutants, while it was inhibited in Ran1Q70L mutants. Importantly, artificial accumulation of AIF in the parental MAC rescued PND progression defects in RAN1 knockdown mutants. These data suggest that Ran1 is essential for parental macronuclear import of AIF and PND in T. thermophila.
Related Concept Videos
Nuclear Localization Signals and Import
Nuclear Fission
Non-nuclear Inheritance
Parental Care
Apoptosis
Protein Import into the Peroxisomes
Peroxisomal Protein Import:
Peroxisomes lack the genetic machinery required to code for their own proteins. Hence, most peroxisomal membrane, lumenal and transmembrane proteins are synthesized in the cytoplasm or ER and transported to the peroxisome...

