What is SRP?

[KTK]

Hi,
What does a signal recognition particle look like and what are its functions? (does anyone happen to know of any good websites that could clarify these specific questions for me ) and how would one carry out an experiment to trace the movemnet of the polypeptide from the time it is synthesized to its secretion from the cell? and what does it mean that a polypeptide is post-translationally modifeid by N-glycosylation?
Thanks,
KTK

[tbrahim]

Signal Reconition protein. Involved with the docking of ribosomes to the ER membrane. Couldn't give a structure. Look for in biochemistry sites or journals if you go to a University. As for tracing peptides or any protein there are definatly different methods. One that comes to mind would be to use a pulses chase using a temperature sensitive virus. this will allow one to stop protein of interest from migration out of the ER. A flourecent tag(GFP) can be used to visualize at different times. You can also do a number other things like measuring colocalization of peptides but that is another topic. N-linked glycosylation post-translationatle speakes for itself. It is done in the ER(after tranlation of course) and is trimed in the Golgi. Hope this helps

[KTK]

How would you determine if a particular protein, whose amino acid sequence is known, is syntheized as a cytosolic protein a secretory protein or a nuclear protein?