Transcript CF Class Presentation LR

Cystic Fibrosis
From Gene to Protein
Class instructions
In this lesson
• Look at the normal and mutated CFTR gene
• Make messenger RNA (mRNA) from DNAtranscription
• Make protein from mRNA- translation
The devil is in the detail!
• The 5’ prime and 3’ prime ends of the
bases must be round the right way!
IMPORTANT:
Do not take
bases apart!!!
Correct base pairing is critical!
• Green (Guanine)
pairs with yellow
(Cytosine)
• Blue (Adenine) pairs
with orange
(Thymine)
Lesson – part 1
Normal CFTR Gene
ΔF508 CF Mutation
Sense
Sense
Antisense
Antisense
Transcription – Step 1
Base pairing in mRNA- use brown
sugars
• Green (Guanine)
pairs with yellow
(Cytosine)
• Blue (Adenine) pairs
with light blue (Uracil)
Transcription – Step 2
• To make an mRNA, you must use the
antisense (red sugars) strand as as the
template as base pairing is complimentary.
Resulting mRNA
Normal CFTR mRNA
ΔF508 CFTR mRNA
Translation
• Turns mRNA into protein
• Use transfer RNA (tRNA) which are
attached to amino acids as intermediate
• Amino acids have a direction too!
N-terminal
C-terminal
Transfer RNA
UAA
Isoleucine
CAA
Valine
CCA
Glycine
AAA
Phenylalanin
e
UAA
Isoleucine
tRNA – holds an anticodon at one end, and an amino acid at the
other
Using mRNA in 5’-3’
orientation, translate into
protein.
Separate tRNA & protein from
mRNA
Resulting protein
Normal CFTR
protein
Isoleucine – Phenylalanine Glycine
ΔF508 CFTR
protein
Isoleucine – Glycine Valine
Polymerase Chain Reaction
• Using the original chromosomes, separate
strands
• Find where primers stick to each strand
Genetic Test
• Using the original chromosomes, see what
a PCR product will look like.
• Remember: Each individual will have 2
chromosomes - one inherited from mother
and one from father.
DNA gel genetic test result