Lesson 3 Translation From RNA to protein translation

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Lesson 3: Translation

Lesson 3: Translation

From RNA to protein: translation The genetic code Three possible “reading frames” THE ABC

From RNA to protein: translation The genetic code Three possible “reading frames” THE ABC FOR THE DNA Insertion (X) or Deletion (B) THE AXB CFO RTH EDN A THE ACF ORT HED NA

Ribosomes in the cytoplasm of a eukaryotic cell

Ribosomes in the cytoplasm of a eukaryotic cell

Composition of eukaryotic ribosomes

Composition of eukaryotic ribosomes

RNA-binding sites in the ribosome Each ribosome has: • a binding site for m.

RNA-binding sites in the ribosome Each ribosome has: • a binding site for m. RNA • three binding sites for t. RNA • A-site: aminoacyl-t. RNA • P-site: peptidyl-t. RNA • E-site: exit

t. RNA molecules: matching amino acids to codons in m. RNA

t. RNA molecules: matching amino acids to codons in m. RNA

Translation of the genetic code: two adaptors that act one after another

Translation of the genetic code: two adaptors that act one after another

m. RNA translation mechanism Step 1: An aminoacyl-t. RNA molecule binds to the A-site

m. RNA translation mechanism Step 1: An aminoacyl-t. RNA molecule binds to the A-site on the ribosome Step 2: A new peptide bond is formed Step 3: The small subunit moves a distance of three nucleotides along the m. RNA chain ejecting the spent t. RNA molecule Step 4: The next aminoacyl-t. RNA molecule binds to the A-site on the ribosome Step 5: . . .

The initiation phase of protein synthesis in eukaryotes 1. Initiation complex (small ribosomal subunit

The initiation phase of protein synthesis in eukaryotes 1. Initiation complex (small ribosomal subunit + initiation factors) binds DNA and searches for start codon 2. Large ribosomal subunit adds to the complex 3. Translation starts 4. .

Prokaryotic vs eukaryotic m. RNA molecules

Prokaryotic vs eukaryotic m. RNA molecules

Structure of a typical prokaryotic m. RNA molecule

Structure of a typical prokaryotic m. RNA molecule

5´ end capping of eukaryotic m. RNA molecules

5´ end capping of eukaryotic m. RNA molecules

The final phase of protein synthesis ® binding of release factor to a stop

The final phase of protein synthesis ® binding of release factor to a stop codon terminates translation ® the completed polypeptide is released ® the ribosome dissociates into its two separate subunits

Polyribosomes: several ribosomes can simultaneously translate the same m. RNA molecule

Polyribosomes: several ribosomes can simultaneously translate the same m. RNA molecule

Proteasomes: degradation of “unwanted” proteins in eukaryotic cells

Proteasomes: degradation of “unwanted” proteins in eukaryotic cells

The production of a protein by a eukaryotic cell Many levels of regulation/variation

The production of a protein by a eukaryotic cell Many levels of regulation/variation

Protein import by membrane-bounded organelles ATP !!!

Protein import by membrane-bounded organelles ATP !!!

The role of signal sequences in protein sorting ü proteins destined for the ER:

The role of signal sequences in protein sorting ü proteins destined for the ER: N-terminal signal sequence that directs them ü proteins destined to remain in the cytosol: no signal sequence

Free and membrane-bound ribosomes

Free and membrane-bound ribosomes

ER signal sequence and SRP: directing ribosomes to the ER membrane

ER signal sequence and SRP: directing ribosomes to the ER membrane

Translocation of a soluble protein across the ER membrane

Translocation of a soluble protein across the ER membrane

Integration of a transmembrane protein into the ER membrane

Integration of a transmembrane protein into the ER membrane

Integration of a double-pass transmembrane protein into the ER membrane

Integration of a double-pass transmembrane protein into the ER membrane

Vesicular traffic

Vesicular traffic

Clathrin-coated pits and vesicles

Clathrin-coated pits and vesicles

Selective transport: mediated by clathrin-coated vesicles

Selective transport: mediated by clathrin-coated vesicles

Model of transport vesicle docking

Model of transport vesicle docking

Transport vesicle fusion

Transport vesicle fusion

Protein glycosylation in the ER

Protein glycosylation in the ER

The Golgi apparatus

The Golgi apparatus

Exocytosis: the regulated and constitutive pathways

Exocytosis: the regulated and constitutive pathways

Exocytosis of secretory vesicles

Exocytosis of secretory vesicles

Translation Protein Synthesis RNA protein Making a proteinTranslation Protein Synthesis RNA protein Making a protein
TRANSLATION PROTEIN RNA PROTEIN SYNTHESIS MAKING A PROTEINTRANSLATION PROTEIN RNA PROTEIN SYNTHESIS MAKING A PROTEIN
Translation Protein Synthesis RNA protein Making a proteinTranslation Protein Synthesis RNA protein Making a protein
t RNA t RNA Transfer RNA t RNAt RNA t RNA Transfer RNA t RNA
RNA RNA RNA ribonucleic acid RNA is aRNA RNA RNA ribonucleic acid RNA is a
RNA m RNA informacijska RNA r RNA ribosomskaRNA m RNA informacijska RNA r RNA ribosomska
RNA and Protein Synthesis RNA Compare RNA toRNA and Protein Synthesis RNA Compare RNA to
RNA and Protein Synthesis RNA RNA is aRNA and Protein Synthesis RNA RNA is a
SINTESIS PROTEIN Transfer RNA t RNA m RNASINTESIS PROTEIN Transfer RNA t RNA m RNA
RNA and Protein Synthesis RNA RNA Ribonucleic AcidRNA and Protein Synthesis RNA RNA Ribonucleic Acid
RNA and Transcription DNA RNA PROTEIN RNA andRNA and Transcription DNA RNA PROTEIN RNA and
RNA Protein Synthesis Vocabulary Messenger RNA m RNARNA Protein Synthesis Vocabulary Messenger RNA m RNA
RNA TRANSCRIPTION TRANSLATION RNA RNA ribonucleic acid CarriesRNA TRANSCRIPTION TRANSLATION RNA RNA ribonucleic acid Carries
Lesson 3 Translation From RNA to protein translationLesson 3 Translation From RNA to protein translation
Translation From RNA to Protein RNA carries DNAsTranslation From RNA to Protein RNA carries DNAs
PROTEIN SYNTHESIS TRANSCRIPTION TRANSLATION PROTEIN SYNTHESIS DNA RNAPROTEIN SYNTHESIS TRANSCRIPTION TRANSLATION PROTEIN SYNTHESIS DNA RNA
9 5 Translation RNA to Protein Translation converts9 5 Translation RNA to Protein Translation converts
TRANSLATION DNA Transcription RNA Nucleus Cytoplasm Translation ProteinTRANSLATION DNA Transcription RNA Nucleus Cytoplasm Translation Protein
PROTEIN OUTLINE Protein Definition Protein structure Protein FunctionPROTEIN OUTLINE Protein Definition Protein structure Protein Function
Protein Simple Protein Conjugated Protein Derivative Protein SpecialProtein Simple Protein Conjugated Protein Derivative Protein Special
Protein Yaps Analizi Protein aileleri Protein lokalizasyonu proteinProtein Yaps Analizi Protein aileleri Protein lokalizasyonu protein
Protein Stability Protein Folding Protein Stability Protein stabilityProtein Stability Protein Folding Protein Stability Protein stability
Transcription Translation Protein Synthesis Protein Synthesis Protein synthesisTranscription Translation Protein Synthesis Protein Synthesis Protein synthesis
Translation Making the Protein Translation Overview l TranslationTranslation Making the Protein Translation Overview l Translation