1.Which is the most unlikely involved in the intron-splicing of pre-mRNA ? [a. U1 RNP; b. 5' cap structure; c. polyadenylation signal; d. secondary structure of pre-mRNA], give a brief explanation if you are not sure your answer (5%)

U1A protein inhibits polyadenylation of its pre-mRNA

U1A protein binds U1snRNA: 7-base sequence-U1A binding site

U1A protein inhibits polyadenylation of its pre-mRNA

U1A binding site2 copies in its own mRNA , at 3' end near the poly(A) signalprevent polyadenylation, but not the cleavage of pre-mRNArapidly degraded

U1A protein inhibits polyadenylation of its pre-mRNA

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prevent polyadenylation, but not the cleavage of pre-mRNAtruncated mRNA without poly(A) tail, rapidly degraded

apo-B (apolipoprotein B), serum protein of lipid transporter, CAA UAA, glutamine stop codon, in intestineboth liver and intestine forms transport lipidonly liver apo-B delivers cholesterol containing LDL

RNA editing in mammalian

Na+, Ca+2 ion channel, learning and memoryCAG CIG, glutamate arginine, Ca +2 cannot pass

Both editing of apo-B and glutamate receptor by RNA deaminases

RNA editing in glutamate receptor mRNA

Iron dependent regulation of TfR mRNA stability.

when iron ion high, IRE -BP inactive, cannot bind IRE,TfR mRNA is protected from degradation;when iron is low, IRE-BP is active and binds IRE. then TfR mRNA stability , TfR mRNA degraded

Iron dependent regulation of translation of ferritin stability.

ferritin is an intracellular protein that binds iron ionsferritin, 5' IRE free of BP, translation occurs, more ferritin.The IRE in ferritin mRNA has no AU rich

ferritin

Using Yeast to study Eukaryotic Gene Functionfrom Recombinant DNA (J Waston et al.) Ch 13

Size of genome in the selected organisms

Cloning yeast biosynthetic genes by complementation in E.coli

Yeast biosynthetic genes are cloned by complementation of E.coli mutations

Classes of yeast vectors

Shuttle vectors replicatein both E.coli and yeast

Cloning a yeast gene by complementation

Yeast genes can be cloned by simple complementation

Generation of temperature sensitive mutants of yeast

Replica plating

Gene targeting by homologous recombination

Homolgous recombination is a relative frequent event in yeast

Replacing a gene by transplacement

Tetrad analysis

Cloning genes required for matingreveals a signaling pathway similarto that seen in higher organisms

Pheromone signaling pathway

Cloning of the GPA1 gene as a high-copy suppressor of pheromone sensitivity

This fragment DNA only works in high copies, suggesting it was acting as a suppressor

The receptor swap experiment

Genetic experiments in yeast can answer precise biochemical questions

U2 RNA base-pairs with an intron sequence

Base pairing between U2 and branch point (in yeast)

A genetic assay for protein-protein interactions

Plasmid shuffle

Genetic analysisin yeast can be exploited to identify and studygenes from higher organisms