In the absence of Ca2+, muscle is relaxed

TM blocks myosin’s interaction with F-actin

TLS Online TPP Program

#Id: 8849

#Section 3: Genetics, Cellular and Molecular Biology

Phosphorylation of MCM helicase activators by G1/S phase CDKs and S phase CDKs, prevents reloading of MCM helicases (ensuring that replication from each origin occurs only once during each cell cycle)

TLS Online TPP Program

#Id: 8850

#Section 3: Genetics, Cellular and Molecular Biology

Geminin 

a small protein,, that contributes to the inhibition of re-initiation at origins until cells complete a full cell cycle.

TLS Online TPP Program

#Id: 8851

#Section 3: Genetics, Cellular and Molecular Biology

Geminin is expressed in late G1; it binds to and inhibits Cdt1 preventing reloading of the MCM helicase.

TLS Online TPP Program

#Id: 8852

#Section 3: Genetics, Cellular and Molecular Biology

Geminin contains a destruction box at its N-terminus that is recognized by APC/Ccdh1, causing it to be ubiquitinylated in late anaphase and degraded by proteasomes.

TLS Online TPP Program

#Id: 8853

#Section 3: Genetics, Cellular and Molecular Biology

Cohesins 

The protein ring complexes that establish linkages between sister chromatids

TLS Online TPP Program

#Id: 8854

#Section 3: Genetics, Cellular and Molecular Biology

Cohesins establish linkages between the replicated DNA molecules, which are essential for their accurate segregation later in the cell cycle. This linking mechanism is coupled to DNA replication.