TLS Online TPP Program

#Id: 6897

#Unit 3. Fundamental Processes

HP1 is recruited to regions in which histone H3 has been methylated at lysine 9, a modification involved in heterochromatin formation. It turns out that HP1 can also interact with Dnmt1, which can promote DNA methylation in the vicinity of HP1 binding. Furthermore, Dnmt1 can directly interact with the methyltransferase responsible for H3K9 methylation, creating a positive feedback loop to ensure continued DNA and histone methylation.

TLS Online TPP Program

#Id: 8170

#Unit 2. Cellular Organization

In yeast Rab protein is the Sec4 and its effectors are exocyst and Type V Myosin.

TLS Online TPP Program

#Id: 10100

#Unit 4. Cell Communication and Cell Signaling

Desmosomes

Adhesion type- Cell-cell

Cytoskeletal attachment- Intermediate filaments

TLS Online TPP Program

#Id: 6149

#Unit 3. Fundamental Processes

Ku70, Ku80, DNA-PKcs, Artemis, XRCC4, Cernunnos-XLF, and DNA ligase IV. Ku70 and Ku80 are the most fundamental components of NHEJ. 

They constitute a heterodimer that binds to the DNA ends and recruits DNA-PKcs, which is a protein kinase. DNA-PKcs, in turn, forms a complex with Artemis. Artemis is both a 5’-to-3’ exonuclease and a latent endonuclease that is activated by phosphorylation by DNA-PKcs. 

These nucleolytic activities process the broken ends and prepare them for ligation. Ligase IV performs ligation in a complex with XRCC4 and Cernunnos-XLF.

TLS Online TPP Program

#Id: 9716

#Unit 4. Cell Communication and Cell Signaling

Ste7, phosphorylates and activates Fus3,  a serine/threonine kinase