Protein Sorting Flashcards
ER = _____________
Structure
• made of ___________________.
• has only one ____________________.
• _____________ are attatched to the surface of ER
Rough ER is involved in ________________.
Smooth ER is associated with ____________, calcium storage and ______________.
ER = ENDOPLASMIC RECTICULUM
Structure
• made of FLATTEN SACS AND TUBULES
• has only one LIPID BILAYER MEMBRANE
• RIBOSOMES are attatched to the surface of ER
Rough ER is involved in ___________.
Smooth ER is associated with LIPID SYNTHESIS , calcium storage and DETOXIFICATION.
Put these in order:
A. Lysosomes B. Golgi C. Vesicular formations D. ER
E. Nucleus
- Nucleus
- ER
- Golgi
- Lysosomes
- Vesicular formations
What are the two different kinds of protein targeting?
Signal-based targeting
Secretory pathway
What are the 4 elements needed got targeting to intracellular organelles?
- Targeting Sequence
- Organelle Receptor Proteins
- Translocation channel
- Energy source
Name the term
5 elements of protein sorting
______________= located at the N-terminus of a protein (first part to be synthesised
____________ = allows proteins to pass into or through membrane bilayer
__________ = couples translocation with an energy source
_____________ = each organelle carries these and binds to targeting sequences to ensure specificity
TARGETING SEQUENCE = located at the N-terminus of a protein (first part to be synthesised
TRANSLOCATION CHANNEL = allows proteins to pass into or through membrane bilayer
ENERGY SOURCE = couples translocation with e.g hydrolysis of GTP
ORGANELLE RECEPTOR PROTEINS = each organelle carries these and binds to targeting sequences to ensure specificity
_____________ regulates the transport of molecules between the nucleus and the cytoplasm
It is embedded in the ____________ and it can be known as a “_____________”
Nuclear proteins that travel through include: 3 things?
THE NUCLEAR PORE COMPLEX regulates the transport of molecules between the nucleus and the cytoplasm
It is embedded in the NUCLEAR ENVELOPE and it can be known as a “SELECTIVE BARRIER ”
Nuclear proteins that travel through include:
HISTONES
DNA AND RNA POLYMERASES
TRANSCRIPTION FACTORS
What are the three types of nucleoporins?
- Structural nucleoporins
2, Membrane nucleoporins - FG-nucleoporins
Structural nucleoporins have a _______ type structure.
7 of theses make a ring called the __________ that lies between membranes.
Structural nucleoporins have a Y-SHAPED type structure.
7 of theses make a ring called the Y-COMPLEX that lies between membranes.
FG-nucleoporins
• contain multiple repeats of _______ repeats, and_________ polypeptide chains
• Forms a ________ matrix within central channel of _______
• composes a hydrophobic barrier that creates ______________ of the NPC.
• Acts like a “___________”
FG-nucleoporins
• contain multiple repeats of HYDROPHOBIC repeats, and HYDROPHILLIC polypeptide chains
• Forms a GEL-LIKE matrix within central channel of NPC
• composes a hydrophobic barrier that creates SELECTIVE PERMEABILITY of the NPC.
• Acts like a “SIEVE”
What are the two key proteins that drive the import of proteins into the nucleoplasm?
IMPORTIN and RAN
How are proteins imported into the nucleoplasm….
A cargo protein bind to an _____ creating an ___________,
It then diffuses through the ______ by interacting with ______________.
In the nucleoplasm _________ binds to the importin, releasing the cargo protein.
To support another cycle the _____________ complex moves back to the cytoplasm
___________ stimulates Ran to hydrolyse the bound GTP
________ is returned to the nucleoplasm
A cargo protein bind to an IMPORTIN creating an IMPORTIN-CARGO PROTEIN COMPLEX
It then diffuses through the NPC by interacting with FG-NUCLEOPORINS.
In the nucleoplasm RAN x GTP binds to the importin, releasing the cargo protein.
To support another cycle the RAN x IMPORTIN x GTP complex moves back to the cytoplasm
GAP stimulates Ran to hydrolyse the bound GTP
________ is returned to the nucleoplasm
