GTP promotes the formation of early-import intermediates but is not required during the translocation step of protein import into chloroplasts
Journal Article
·
· Plant Physiology (Bethesda)
Protein import into chloroplasts is an energy-requiring process mediated by a pertinacious import apparatus. Although previous work has shown that low levels of ATP or GTP can support precursor binding, the role of GTP during the import process remains unclear. Specifically, it is unknown whether GTP plays a separate role from ATP during the early stages of protein import and whether GTP has any role in the later stages of transport. The authors investigated the role of GTP during the various stages of protein import into chloroplasts by using purified GTP analogs and an in vitro import assay. GTP, GDP, the nonhydrolyzable analog GMP-PNP, and the slowly hydrolyzable analogs guanosine 5{prime}-O-(2-thiodiphosphate) and guanosine 5{prime}-O-(3-thiotriphosphate) were used in this study. Chromatographically purified 5{prime}-guanylyl-imido-diphosphate and guanosine 5{prime}-O-(3-thiotriphosphate) were found to inhibit the formation of early-import intermediates, even in the presence of ATP. The authors also observed that GTP does not play a role during the translocation of precursors from the intermediate state. They conclude that GTP hydrolysis influences events leading to the formation of early-import intermediates, but not subsequent steps such as precursor translocation.
- Research Organization:
- Michigan State Univ., East Lansing, MI (US)
- Sponsoring Organization:
- National Science Foundation; US Department of Energy
- OSTI ID:
- 20006207
- Journal Information:
- Plant Physiology (Bethesda), Journal Name: Plant Physiology (Bethesda) Journal Issue: 1 Vol. 121; ISSN 0032-0889; ISSN PLPHAY
- Country of Publication:
- United States
- Language:
- English
Similar Records
( sup 32 P)3 prime -O-(4-benzoyl)benzoyl ATP as a photoaffinity label for a phospholipase C-coupled P2Y-purinergic receptor
Guanosine 5'-triphosphate (GTP) binding to Guinea pig liver transglutaminase modulates enzyme activity
Evidence for a vasopressin receptor-GTP binding protein complex
Journal Article
·
Wed Aug 15 00:00:00 EDT 1990
· Journal of Biological Chemistry; (USA)
·
OSTI ID:6622991
Guanosine 5'-triphosphate (GTP) binding to Guinea pig liver transglutaminase modulates enzyme activity
Conference
·
Thu May 01 00:00:00 EDT 1986
· Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)
·
OSTI ID:5127024
Evidence for a vasopressin receptor-GTP binding protein complex
Conference
·
Thu May 01 00:00:00 EDT 1986
· Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)
·
OSTI ID:5019982