β-catenin binds to TCF to displace the Gro repressor and recruits co-activator proteins Pygo, LGS, to activate target gene expression.

TLS Online TPP Program

#Id: 8858

#XL - T Zoology

Cohesin-mediated cohesion between sister chromatids is established by a two-step process:

1.Loading and unloading of cohesins

2. Stabilization of cohesins

TLS Online TPP Program

#Id: 8859

#XL - T Zoology

During G1, 

cohesins associate with chromosomes by cohesin loading factors Scc2 and Scc4 and unloaded continuously by a cohesin associated complex Pds5 and Wap1 proteins. 

TLS Online TPP Program

#Id: 8860

#XL - T Zoology

During S phase

DNA-bound G1 cohesins Convert into cohesive complexes by cohesin acetyl transferases (CoATs)

which acetylate Smc3 subunit & prevents unloading of cohesins by Pds5-Wapl, thereby stabilizing the cohesins on chromosomes.

TLS Online TPP Program

#Id: 8862

#XL - T Zoology

In vertebrates, stabilization of cohesins requires the cohesin-associated factor sororin.

TLS Online TPP Program

#Id: 8864

#XL - T Zoology

Defects of cohesin’s gene expression regulation function are the cause of a group of diseases collectively called cohesinopathies.

TLS Online TPP Program

#Id: 8865

#XL - T Zoology

The phosphorylation state of T14 and Y15 is controlled by a dual-specificity protein kinase known as Wee1 and a pair of dual-specificity phosphatases, Cdc25B and Cdc25C (Threonine 14 is not phosphorylated in S. pombe CDK1)