Two points separated by 80 bp in the free double helix may actually be one on another on nucleosome surface.

 

TLS Online TPP Program

#Id: 3209

#Unit 4. Cell Communication and Cell Signaling

Dominant gain-of-function mutations in proto-oncogenes and recessive loss-of-function mutations in tumor-suppressor genes are oncogenic.

TLS Online TPP Program

#Id: 3210

#Unit 4. Cell Communication and Cell Signaling

TLS Online TPP Program

#Id: 3211

#Unit 4. Cell Communication and Cell Signaling

Three mechanisms can produce oncogenes from the corresponding proto-oncogenes:
Point mutation
Chromosomal translocation
Amplification

TLS Online TPP Program

#Id: 3212

#Unit 4. Cell Communication and Cell Signaling

Point mutation (i.e., a change in a single base pair) in a proto-oncogene that results in a hyperactive or constitutively active protein product.

TLS Online TPP Program

#Id: 3213

#Unit 4. Cell Communication and Cell Signaling

TLS Online TPP Program

#Id: 3214

#Unit 4. Cell Communication and Cell Signaling

Amplification (i.e., abnormal DNA replication) of a DNA segment including a proto-oncogene, leading to overproduction of the encoded protein.