collagen synthesis- FA v UW

[You'reCrazy]

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hey all,

wondering if you guys could help me........

pg 92 of FA says that collagen is hydroxylated in the ER and then glycosylated (on the lysine residues) and formed into a triple helix by the Golgi but a question explanation on UW said that during collagen synthesis both hydroxylation, glycosylation, and triple helix formation all occur in the ER.

anyone know which is right?

thanks

 

[Prop]

FA made a mistake on that one.

I actually looked at this question for some minutes myself, and decided to look it up (in 2 different books).
Turns out UW is right. Hydroxylation, glycosylation, and triple helix formation all take place in the ER. The Golgi apparatus is only for packaging in secretory vesicles (as it is for all proteins).

Hope this helps.

Prop

 

[kwanny]

yeah, i noticed that discrepancy too, but I don't think FA is wrong. The hydroxylation being in Golgi had been in FA for the past few years. If it had been a mistake, it wouldn't have been left in there for so long.

The conclusion I made was that it can probably happen in both.

 

[You'reCrazy]

just checked Goljan's biochem book, that also says that both hydroxylation and glycosylated in ER.......so who knows.......and as far as FA being wrong, I've seen many errors in this book.......so far it has been pretty unreliable

 

[SOUNDMAN]

According to Robbins, pg 105, states collagen is hydroxylated and gycosylated in the ER. In the Golgi it forms the triple helix via three procollagen chain, that is then secreted from the cell and cleaved by proteases in the ECM....

Hope that helps!