Introduction to molecular biology…biology…

Protein interactionsProteins can form interations: – Proteins complexes, oligomers Proteins can bind to each other depending on their relative charges and structures... We have used the

Introduction to molecular

biology…

(…in one hour!!) Stephen Edwards

Eukaryotic cell

DNA

Contained in the nucleus

Arranged in 22 chromosomes, plus two sex chromosomes

Two copies of each

99.9% identical to other humans, 98% to chimp!

Around 2m DNA, enough to travel to sun and back 600 times!

Therefore, very tightly packed

5' C-G-A-T-T-G-C-A-A-C-G-A-T-G-C 3' | | | | | | | | | | | | | | | 3' G-C-T-A-A-C-G-T-T-G-C-T-A-C-G 5'

DNA function

Carries the blueprint for life

Duplication for new cells

Make proteins for biological functions:

DNA is grouped into threes (codons)

AGTTTTGGGCCCAAA

Start and stop codons

mRNA is then modified…

…and travels out of the nucleus

mRNA splicing

Alternative splicing

Protein structure

Protein interactions

Proteins can form interations:

– Proteins (complexes, oligomers)

Proteins can bind to each other depending

on their relative charges and structures

Gene expression regulation

Common abbreviations

EST expressed sequence tag

SNP single nucleotide polymorphism ORF open reading frame

UTR untranscribed region

We have used the yeast two-hybrid system to identify proteins that interact with the

intracellular portion of the hepatocyte growth factor (HGF) receptor (Met) We isolated a human cDNA encoding a novel protein of 68 kDa, which we termed FAP68 This protein is homologous to a previously described FK506-binding protein-associated protein, FAP48, which derives from an alternative spliced form of the same cDNA, lacking an 85-nucleotide exon and leading to an early stop codon Here we show that epithelial cells, in which the HGF receptor is naturally expressed, contain FAP68 and not FAP48 proteins FAP68

binding to Met requires the last 30 amino acids of the C-terminal tail, which are unique to the HGF receptor Indeed, FAP68 does not interact with related tyrosine kinases of the Met and insulin receptor families FAP68 interacts specifically with the inactive form of HGF receptor, such as a kinase-defective receptor or a dephosphorylated wild type receptor Evidence

In vivo, endogenous FAP68 can be coimmunoprecipitated with the HGF receptor in the absence of stimuli and not upon HGF stimulation Thus, FAP68 represents a novel type of effector that interacts with the inactive HGF receptor and is released upon receptor

phosphorylation Free FAP68 exerts a specific stimulatory activity toward the downstream target p70 S6 protein kinase (p70S6K) Significantly, nonphosphorylated HGF receptor prevents FAP68 from stimulating p70S6K These data suggest a role for FAP68 in coupling HGF receptor signaling to the p70S6K pathway

Future of molecular biology

Personalised medicine

Target-specific drugs (e.g adipose tissue) Gene therapy

Comparative genomics

Molecular biology information

Gene/Protein naming conventions

– Bioinformatics 2005 Jan 15;21(2):248-56 Epub 2004 Aug 27 Gene name ambiguity of eukaryotic nomenclatures.Chen L, Liu H, Friedman C

Two hybrid system