Mitochondria Export Sulfur Species Required for Cytosolic tRNA Thiolation

作者：Pandey Alok; Pain Jayashree; Dziuba Nathaniel; Pandey Ashutosh K; Dancis Andrew; Lindahl Paul A; Pain Debkumar^*

来源：Cell Chemical Biology, 2018, 25(6): 738-+.

DOI：10.1016/j.chembiol.2018.04.002

In eukaryotes, mitochondria have been hypothesized to generate sulfur species required for tRNA thiolation in the cytosol, although no direct evidence thus far exists. Here we have detected these sulfur species, making use of our observation that isolated yeast cytosol alone is unable to thiolate tRNAs but can do so upon addition of mitochondria. Mitochondria were found to utilize the cysteine desulfurase Nfs1 to produce sulfur-containing species with masses ranging from 700 to 1,100 Da. Mitochondria exported these species via the Atm1 transporter in the inner membrane. Once exported to the cytosol, these sulfur species promoted cytosolic tRNA thiolation with no further requirement of mitochondria. Furthermore, we found that the Isu1/2 scaffolds but not the Ssq1 chaperone of the mitochondria! ironsulfur cluster machinery were required for cytosolic tRNA thiolation, and thus the sulfur utilization pathway bifurcates at the Isu1/2 site for intra-organellar use in mitochondria or export to the cytosol.

• 出版日期2018-6-21
• 单位rutgers