Enderecamento de subcelular proteinas 1 Flashcards
Como é que cada proteína é endereçada para o
local onde tem que realizar a sua função?
-Transporte fechado
-Transporte transmembranar
-Transporte vesicular
Onde sao sinal enderecamentos formados?
No ribosomas
A sequencia de sinais e constituida por :
N- terminal short amino acid sequences
In what target organelle is the sequence signal hydrophobic?
Endoplasmic reticulum
What is the process of sending a protein to the Endoplasmic reticulum?
Ribosome (Protein +signal)– +Signal Receptor Particle– collects energy to bind to SRP receptor – Binds to translocator– Translocator becomes active– Signal peptidase cleaves the signal– protein in the E.R Lumen– inactive translocator– signal + new protein
Why is the translocator mostly closed unless activated?
To maintain the calcium ions in the E.R which are used for secondary transport
What happens to the Signal recognition particle after the protein binds to the translocator?
It is removed and reused in another protein
Why is the sequencial signal co-translational?
Because it is taking the proteins to the E.R while they are still being synthesized by ribosomes (or in this case where the mRNA is being decoded into polypeptide chains, hereby translated)
What is the translation process as the proteins are being transported to the E.R?
The SRP causes a stop or slow down in translation, and it continues again after the protein and signal binds to the translocator on the E.R
Como se investiga o endereçamento subcelular por sequências
específicas de amino-ácidos?
Atraves da fusao das sequencias codificantes de sequencial sinal hipoteticas com o gene de uma proteina fuorescente
What binds the ribosomes to the Endoplasmic Reticulum?
Multiple nascent polypeptide chain with the translocator on the E.R lumen
durante a transferência da cadeia polipeptídica, apesar de aberto, o poro do
translocador permanece impermeável ou permeavel à passagem de pequenas moléculas e iões?
Impermeavel
O que e que a sequencia sinal-ancora de paragem faz?
Torna o translocador
modifica a sua conformação, e
descarrega a proteína
lateralmente na membrana
