Class II MHC transcriptional activator called CIITA and another transcription factor called RFX, have both been shown to activate the promoter of class II MHC genes.

Defects in these transcription factors cause one form of bare lymphocyte syndrome.

TLS Online TPP Program

#Id: 8933

#Unit 2. Cellular Organization

TLS Online TPP Program

#Id: 8934

#Unit 2. Cellular Organization

Spindle assembly checkpoint pathway is active until every single kinetochore has attached properly to spindle microtubules

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