de.mpg.escidoc.pubman.appbase.FacesBean
English
 
Help Guide Disclaimer Contact us Login
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

Double prenylation by RabGGTase can proceed without dissociation of the mono-prenylated intermediate

MPS-Authors

Thomä,  Nicolas H.
Max Planck Institute of Molecular Physiology, Max Planck Society;

Niculae,  Anca
Max Planck Institute of Molecular Physiology, Max Planck Society;

http://pubman.mpdl.mpg.de/cone/persons/resource/persons98693

Goody,  Roger S.
Abt. III: Physikalische Biochemie, Max Planck Institute of Molecular Physiology, Max Planck Society;

http://pubman.mpdl.mpg.de/cone/persons/resource/persons98674

Alexandrov,  Kirill
Abt. III: Physikalische Biochemie, Max Planck Institute of Molecular Physiology, Max Planck Society;

Locator
There are no locators available
Fulltext (public)
There are no public fulltexts available
Supplementary Material (public)
There is no public supplementary material available
Citation

Thomä, N. H., Niculae, A., Goody, R. S., & Alexandrov, K. (2001). Double prenylation by RabGGTase can proceed without dissociation of the mono-prenylated intermediate. Journal of Biological Chemistry, 276(52): 1, pp. 48631-48636. Retrieved from http://www.jbc.org/cgi/content/abstract/276/52/48631.


Cite as: http://hdl.handle.net/11858/00-001M-0000-0014-0F7A-3
Abstract
Rab geranylgeranyltransferase (RabGGTase) catalyzes the prenylation of Rab proteins. Despite possessing a single active site, RabGGTase is able to add geranylgeranyl moieties onto each of the two C-terminal cysteine residues of Rab. We have studied the kinetics of Rab double prenylation employing a combination of a novel high pressure liquid chromatography (HPLC)-based in vitro prenylation assay and fluorescence spectroscopy. Transfer of the first geranylgeranyl group proceeds with a k(1) = 0.16 s(-1), while the conversion from singly to double prenylated Rab is 4-fold slower (k(2) = 0.039 s(-1)). We found that following the first transfer reaction, the conjugated lipid is removed from the active site of RabGGTase but mono-prenylated Rab.REP complex remains bound to RabGGTase with a K-d < 1nM. In contrast to the doubly prenylated Rab7.REP dissociation of the mono-prenylated species from RabGGTase was only weakly stimulated by phosphoisoprenoid. Based on the obtained rate constants we calculated that at least 72% of mono-prenylated Rab molecules proceed to double prenylation without dissociating from RabGGTase. The obtained data provides an explanation of how RabGGTase discriminates between mono-prenylated intermediate and double prenylated reaction product. It also indicates that the phosphoisoprenoid acts both as a substrate and as a sensor governing the kinetics of protein-protein interactions in the double prenylation reaction.