Cell biology Flashcards
(26 cards)
Overall what does p53 do?
transient G1 cell cycle arrest in
response to DNA damage to allow genome
repair
what syndrome is caused by gremlin p53 loss of function mutation?
Li-Fraumeni
What mutation causes FAP?
APC
What feature of kinases mean that loss of one protein means that only 1/4 are functional?
Dimerisation of kinases
definition of oncogenes?
changed version (by mutation or altered expression) of a gene normally responsible for cellular growth that causes cancerous growth.
how is a protocol oncogenes different?
proto-oncogen is the normal gene responsible for
cell growth.
How is philedelphoa chromosome treated?
tyrosine kinase inhibitors e.g. Imatinib /
Dasatinib
What does inversion within chromosome 2 cause?
EML4-ALK – > constitutive dimerisation and activation
associated with NSCLC
What causes loss of genes?
- Aneuploidy
- Unequal cross over
- Large deletions
What causes genes amplification?
- Aneuploidy
- DNA Replication Errors
- Unequal Crossover (Ectopic Recombination)
- Retrotransposition(viral)
Examples of point muatution?
- Missense
- Truncation
- Synonymou
E.G no frame shift
What is a driver mutation?
implicated in oncogenesis, is selected for
What is siRNA screens?
anticodon for mRNA leading to silencing of the respective protein synthesis.
This can be used to filter noice from experiments…
methods of filtering the “noise” from biological expression?
western blott (protein)
seRNA screens
mutation assessors
How do mutation assessors work?
Interspecies genome compared to show for essential (or not) nucleotide variation for mutation.
What is a colony formation assay?
cell ability to muiltiply into colonies.
can be used with chemicals to show TS or oncogenes
What is a gene promotor?
DNA sequence which initiates transcription
What is a response element?
DNA sequence within a promotor which binds to a specific transcription factor
What is a gene enhancer?
Short DNA sequence which binds to protein (distal from gene)
What are the steps for gene transcription?
- initiation
- Elongation
- Termination
What happens to CgP islands with gene transcription?
Methylation causing transcription silencing
What types of epigenetic are there?
DNA methylation
Histone modification
Gene imprinting
How does histone modification alter gene expression?
Methylated DNA or histone acetylation causes nucleosomes to pack together stopping entrance of transcription factors
What is gene imprinting?
Methylation or histone modification causes only 1 gene
