Rec8 is the meiosis-specific kleisin; Rad21 is the mitotic kleisin. Nuclear localization of cohesin subunits including Rad21 is assayed.

Establishment of sister chromatid cohesion occurs during S phase; failure to establish cohesion causes M-phase arrest and loss of viability.

Rad21 forms a stable complex with Psm1 and Psm3; cohesin is enriched at broad centromere regions; Rad21 is cleaved specifically in anaphase (essential though only <5% cleaved); Mis4 loads Rad21 onto chromatin.

Eso1 establishes cohesion coupled to replication; Pds5 hinders establishment until counteracted by Eso1 but stabilizes cohesion once established.

rad21-K1 cohesion loss activates the Mad2/Bub1 spindle checkpoint due to diminished microtubule-kinetochore interaction.

Substitutive Rad21 relocates to centromeres in rec8 mutants and directs bipolar (equational) meiosis-I attachment; Rec8 and Rad21 define monopolar and bipolar attachment respectively.

rad21 is essential for mitotic growth; the radiation-sensitive rad21-45 mutant is DSB-repair-deficient and plasmid-borne rad21 fully restores DSB repair.

Interphase separase cleavage of cohesin is required for DNA repair; cohesin is hyper-modified after UV in a Rad3-dependent manner.

Genome-wide GFP localization assigns Rad21 to the nucleus.

rad21-K1 cells were directly imaged to test how defective centromeric cohesion affects kinetochore biorientation and correction of merotelic attachments during anaphase.

Full-text Fig. S2 reports direct ChIP enrichment of Rad21 and the cohesin loader Mis4 at heterochromatin islands over meiotic genes in vegetatively growing cells.

The reconstituted four-subunit fission yeast cohesin (Psm1, Psm3, Rad21, Psc3) binds dsDNA (ATP-independent) and topologically loads onto DNA in an ATP-dependent, loader-stimulated manner.

Aurora B promotes dissociation of Swi6/HP1 and cohesin Rad21 from telomeres for telomere dispersion.

Rad21 is enriched at centromeres, some RNA genes, and subtelomeric regions, with a genomic distribution distinct from condensin Cut14.

Cohesin ATPases interface with regulators (Eco1, Wpl1) to modulate DNA tethering critical for cohesion, DNA repair and transcriptional regulation.

The kleisin Rad21 bridges the SMC ATPase heads; Wapl disengages the kleisin (after ATP rebinds) to open the ring for DNA exit.

The purified fission yeast cohesin ring mediates DNA-DNA tethering, the biochemical basis of sister chromatid cohesion.

The Psm1-Rad21 and Psm3-Rad21 interfaces govern cohesin's hold/release of DNA; destabilizing them can bypass Cut1 cleavage.

Cohesin is a ring-shaped ATPase that topologically embraces DNA; Mis4 DNA binding promotes topological entrapment by the ring.

Cohesin extrudes DNA loops, reflecting chromatin domain formation.

Rad21 is a nuclear, cell-cycle-regulated phosphoprotein with an NLS in the C-terminal third, multiply phosphorylated on serines, peaking near G1/S.

The recovered PMID:22144463 full text directly reports Rad21 and Mis4 ChIP enrichment at meiotic-gene heterochromatin islands in vegetative cells, supporting the base localization while raising concern about the meiotic-cell-cycle extension.