Elucidation of molecular mechanisms of chloroplast protein import

2017 Fiscal Year Final Research Report

• Project/Area Number: 26291060
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Plant molecular biology/Plant physiology
• Research Institution: Osaka University
• Principal Investigator: NAKAI MASATO 大阪大学, たんぱく質研究所, 准教授 (90222158)
• Project Period (FY): 2014-04-01 – 2018-03-31
• Keywords: chloroplast / protein import / protein translocation / translocon / organelle / biogenesis

Outline of Final Research Achievements

Virtually all chloroplasts/plastids in today’s photosynthetic/plastid-containing eukaryotes derive from one successful primary endosymbiotic event with a cyanobacterium-like ancestor. During evolution, massive transfer of genes from the endosymbiont to the host’s nuclear genome occurred concomitant with establishment of a protein transport system that allows these nucleus-encoded proteins back into the endosymbiotic organelle. Two successive protein translocons at the outer and inner envelope membranes of chloroplast, termed TOC and TIC, respectively, are responsible for this protein transport. We previously identified a novel inner envelope membrane protein complex consisting of Tic20, Tic56, Tic100, and Tic214 (Ycf1) in Arabidopsis. Furthermore, we have recently identified a completely novel ATPase complex at the inner envelope which functions as the TIC(20/56/100/214)-associated ATP-driven import motor for preprotein translocation.

Free Research Field

Plant Molecular Cell Biology