Transcription factors regulate the transcription of genes by binding to DNA. They can either activate or repress transcription. Transcription factors bind to specific DNA sequences near a gene's promoter or farther away. Many factors can influence transcription, including transcription factors that regulate development of tissues like the cornea, factors that influence longevity, and factors involved in processes like transcription elongation and repairing DNA damage during transcription. Environmental stressors were also found to not affect transcription of the L1 retrotransposon from human genes.

1. Topic: Factors affecting
Transcription
Submitted To: Sir Naeem Abbas
Submitted By: Ayesha Masood
Roll no :17411506022
Semester 7
Subject: Molecular Biology
University of Chakwal

2. Transcription:-
The synthesis of RNA molecules using DNA strands as
the templates so that the genetic information can be
transferred from DNA to RNA.
Fig 1

3. Transcription Factors:-
 Are proteins that regulate the transcription of genes.
 Involved in the process of converting, or transcribing,
DNA into RNA.
 Include a wide number of proteins, excluding RNA
polymerase, that initiate and regulate the transcription
of genes

4. How do transcription factors work?
 Transcription factor binds to DNA at a certain
target sequence.
 Transcription factors that are activators boost a
gene's transcription.
 Groups of transcription factor binding sites
called enhancers and silencers can turn a gene
on/off in specific parts of the body.

5. Activity for transcription factor
Fig 2

6. Activation:-
 Some transcription factors activate transcription.
 They may help the general transcription factors and/or
RNA polymerase bind to the promoter.
Fig 3

7. Repression:-
 Other transcription factors repress transcription.
 This repression can work in a variety of ways.
Fig 3

8. Binding sites:-
 The binding sites for transcription factors are often close
to a gene's promoter.
 Also be found in other parts of the DNA, sometimes very
far away from the promoter, and still affect transcription
of the gene.
Fig 4

9. Factors Affecting Transcription:-
Transcription factors regulating corneal development
 Transcription factors affecting corneal development.
 Pax6 serves as a master regulator of eye development.
 the involvement of several transcription factors has
been studied in early embryonic development of the
eye.
 few studies have focused on postnatal maturation of the
cornea.

10. Transcriptional factor
regulation
Fig 5

11. Evolutionary conservation of
Transcription factors affecting longevity:-
 Gene expression can be optimised for health and
longevity through manipulation of transcription
factor (TF) activity.
 Lifespan-determining TFs regulate a plethora of
cellular and organismal functions, including stress
resistance, metabolism and growth.
 their effects on ageing is most likely a reflection of
the conservation of their function in processes, such
as reproduction, growth, and metabolism, that are
important earlier in life.

12. Cotin….
 The increasing number of older people is resulting in an
increased prevalence of age-related diseases.
 the ageing process itself is a potential point of
intervention.
 gene expression can be optimised for health in older
ages through manipulation of transcription factor (TF)
activity.

13. Cotin….
Fig 6

14. Genome-wide analysis of factors affecting transcription
elongation and DNA repair: a new role for PAF and
Ccr4-not in transcription-coupled repair:-
 RNA polymerases deal with a number of obstacles
during transcription elongation that need to be
removed for transcription resumption.
 One important type of hindrance consists of DNA
lesions, which are removed by transcription-
coupled repair (TC-NER).
 Our data provide evidence that subunits of the
SAGA and Ccr4-Not complexes, Mediator, Bre1,
Bur2, and Fun12 affect transcription elongation to
different extents.

15. Cotin…..
Fig 7

16. Environmental factors affecting transcription of the
human L1 retrotransposon. II. Stressors:-
 The reverse transcriptase coded for by long interspersed
nuclear elements for 35% of human genome.
 Retrotransposons cycle through an RNA intermediate with
transcription as the rate limiting step.
 L1Hs promoter activity was analyzed by transfecting an
L1Hs-expressing cell line with plasmids containing one of
two L1Hs promoters fused to the LacZ reporter gene.
 L1Hs promoter activity was then monitored with a β-
galactosidase assay.
 No increase in β-galactosidase activity was observed after
exposure to X-rays or hydrogen peroxide.

17. Cotin…
Fig 8