[Ylide (OP)]

So I'm studying protein transport in my cell biology class and I came across something that's puzzling me.  

Membrane and secreted proteins are transported to the Golgi via vesicles that bud from the rough ER.  The transport is mediated by v-SNARE proteins on the ER that bind to t-SNARE proteins on the Golgi, allowing the vesicle to fuse with the Golgi phospholipid membrane.  Any membrane proteins on the vesicle are integrated into the Golgi membrane.  So my question is, how did the t-SNARE proteins originally become integrated into the Golgi membrane?  My guess is that the Golgi forms from the ER during cell development, integrating necessary t-SNARE and Rab proteins, but I'm not sure.  



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[nilmot]

I think Golgi body is formed from the ER, it's probably smooth ER, not rough ER. Rough ER is responsible for protein synthesis, smooth ER is responsible for lipid, steroids..etc synthesis. But then again it could be both, I'm going around in circles here, not being of much use. Help please.

Tom

[Ylide (OP)]

I checked with the professor over the weekend.  (online class, my only communication w/ him is email)  It is indeed the case that the Golgi forms from the ER during cell development.  I would guess that it's the Rough ER since it needs to take with it the necessary secretory pathway proteins as it splits from the ER.  Dunno for sure, maybe at the point it develops the ER hasn't differentiated into smooth and rough yet.

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