Abstract
The circularly permuted GTPase large subunit GTPase 1 (LSG1) is involved in the maturation step of the 60S ribosome and is essential for cell viability in yeast. Here, an Arabidopsis mutant dig6 (drought inhibited growth of lateral roots) was isolated. The mutant exhibited multiple auxin-related phenotypes, which included reduced lateral root number, altered leaf veins, and shorter roots. Genetic mapping combined with next-generation DNA sequencing identified that the mutation occurred in AtLSG1-2. This gene was highly expressed in regions of auxin accumulation. Ribosome profiling revealed that a loss of function of AtLSG1-2 led to decreased levels of monosomes, further demonstrating its role in ribosome biogenesis. Quantitative proteomics showed that the expression of certain proteins involved in ribosome biogenesis was differentially regulated, indicating that ribosome biogenesis processes were impaired in the mutant. Further investigations showed that an AtLSG1-2 deficiency caused the alteration of auxin distribution, response, and transport in plants. It is concluded that AtLSG1-2 is integral to ribosome biogenesis, consequently affecting auxin homeostasis and plant development.
Highlights
Ribosomes are complexes of RNA and protein molecules that are present in the cytoplasm or attached to the surface of the rough endoplasmic reticulum
The Arabidopsis dig6 mutant was isolated for its reduced lateral root growth (Xiong et al, 2006) from an M2 population generated by ethyl methane sulphonate (EMS) mutagenized Arabidopsis in the Columbia glabrous 1 (Col-gl1) background
A genetic screen and position cloning identified AtLSG1-2 as an important protein involved in several developmental processes in Arabidopsis
Summary
Ribosomes are complexes of RNA and protein molecules that are present in the cytoplasm or attached to the surface of the rough endoplasmic reticulum. They are the primary site for protein synthesis and are called protein factories. Assembly begins in the nucleolus, and pre-subunits are exported to the cytoplasm. Ribosome biogenesis requires the factors involved in processing ribosomal RNA and proteins and a number of trans-acting factors that organize the assembly process. These trans-acting factors include GTP- and ATP-binding proteins that are necessary for several energy-consuming steps
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call