Base excision repair is triggered by directly removing a damaged base from DNA. In E.coli, system include

Uracil DNA glycosylases

AP endonuclease

DNA polymerase I 

DNA ligase

TLS Online TPP Program

#Id: 10522

#Unit 4. Cell Communication and Cell Signaling

In resting cells 

ATP11A and ATP11C, continuously transport phosphatidylserine from the outer to the inner leaflet of the plasma membrane.

TLS Online TPP Program

#Id: 10523

#Unit 4. Cell Communication and Cell Signaling

In resting cells

Phospholipid scramblase XKR8 and TMEM16F would equilibrate phosphatidylserine in both plasma membrane leaflets, is inactive.

TLS Online TPP Program

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#Unit 4. Cell Communication and Cell Signaling

During apoptosis, caspase-3 cleaves both ATP11A and

ATP11C, inactivating them

TLS Online TPP Program

#Id: 10525

#Unit 4. Cell Communication and Cell Signaling

During apoptosis

caspase-3 cleaves the inactive phospholipid scramblase XKR8. 

TLS Online TPP Program

#Id: 10526

#Unit 4. Cell Communication and Cell Signaling

After cleavage by caspase-3, truncated XKR8, together with either basigin (BSG) or neuroplastin (NPTN), undergoes dimerization and activation and translocates

phospholipids in both directions.

TLS Online TPP Program

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#Unit 4. Cell Communication and Cell Signaling

By scramblase, appearance of phosphatidylserine on the outer surface, act as “eat me” signal