Exons are usually short, typically encoding fewer than 100 amino acids

Exon sequences are conserved by the negative selection of individuals in which the sequences have changed.

TLS Online TPP Program

#Id: 8935

#Unit 2. Cellular Organization

TLS Online TPP Program

#Id: 8936

#Unit 2. Cellular Organization

When a kinetochore is unattached, the outer kinetochore component Knl1 is phosphorylated by the checkpoint kinase Mps1.

TLS Online TPP Program

#Id: 8937

#Unit 2. Cellular Organization

Phosphorylated Knl1 binds the checkpoint protein kinase Bub1-Bub3 and checkpoint protein BubR1. These three proteins, recruit the Mad1-Mad2 complex to the kinetochore.

TLS Online TPP Program

#Id: 8938

#Unit 2. Cellular Organization

The Mad1-Mad2 complex bound to a kinetochore adopts the active closed form (Mad2-C) and has the ability to convert inactive open Mad2 (Mad2-O) in the cytoplasm into active closed Mad2 is able to inhibit APC/Ccdc²⁰

TLS Online TPP Program

#Id: 8939

#Unit 2. Cellular Organization

checkpoint factors Bub1-Bub3, BubR1 and Mad2-C Together, these proteins form the mitotic checkpoint complex

TLS Online TPP Program

#Id: 8940

#Unit 2. Cellular Organization

Knl1 eliminating checkpoint protein binding sites at kinetochores. p31comet disassembles the MCC, allowing APC/Ccdc20 to degrade mitotic cyclins and securin to trigger anaphase.