SRP54 Mouse, Unlabeled, Clone: 30, BD

Description

• Ribosomes that exist freely in the cytosol or those attached to the ER are intrinsically the same in their translational properties
• ER-bound ribosomes are responsible for the production of secretory proteins and integral ER, Golgi, lysosomal, and plasma membrane spanning proteins
• Such proteins contain signal sequences that direct their synthesis to the ER membrane
• As the nascent polypeptide emerges from the ribosome, a signal recognition particle (SRP) binds to the signal sequence and serves to couple the ribosome to the protein-translocating machinery in the ER membrane
• Although the SRP is a 325kDa ribonucleoprotein, its 54kDa subunit (SRP54) mediates interaction with, and targeting of, the nascent protein to the ER
• Via its C-terminal M-domain, SRP54 associates with the nascent protein and inhibits its elongation
• This complex binds to the SRP receptor on the ER, the ribosome is delivered to the translocation machinery, SRP is released, and elongation resumes
• Targeting and insertion are tightly coupled to a GTPase cycle that involves SRP54 and SRP receptor
• Although the mechanisms are unclear, release of SRP from the ER-bound complex requires GTP hydrolysis
• Immunofluorescence, Western Blotting