La Trobe University

About: La Trobe University is a education organization based out in Melbourne, Victoria, Australia. It is known for research contribution in the topics: Population & Health care. The organization has 13370 authors who have published 41291 publications receiving 1138269 citations. The organization is also known as: LaTrobe University & LTU.

Essential role of Isd11 in mitochondrial iron–sulfur cluster synthesis on Isu scaffold proteins

Abstract: Mitochondria are indispensable for cell viability; however, major mitochondrial functions including citric acid cycle and oxidative phosphorylation are dispensable. Most known essential mitochondrial proteins are involved in preprotein import and assembly, while the only known essential biosynthetic process performed by mitochondria is the biogenesis of iron–sulfur clusters (ISC). The components of the mitochondrial ISC-assembly machinery are derived from the prokaryotic ISC-assembly machinery. We have identified an essential mitochondrial matrix protein, Isd11 (YER048w-a), that is found in eukaryotes only. Isd11 is required for biogenesis of cellular Fe/S proteins and thus is a novel subunit of the mitochondrial ISC-assembly machinery. It forms a complex with the cysteine desulfurase Nfs1 and is required for formation of an Fe/S cluster on the Isu scaffold proteins. We conclude that Isd11 is an indispensable eukaryotic component of the mitochondrial machinery for biogenesis of Fe/S proteins.

An integrated approach to environmental stress tolerance and life-history variation: desiccation tolerance in Drosophila

Abstract: The availability of metabolic energy provides a general measure of the environmental stress that can be tolerated by organisms, leading to the hypothesis that increased tolerance to a range of environmental stresses will be associated with a reduction in metabolic rate in Drosophila and many other organisms. This hypothesis makes three predictions about genetic variation for stress tolerance: (1) increased stress tolerance will tend to be associated with decreased metabolic rate; (2) genetic correlations between tolerance of different environmental stresses will tend to be positive; (3) stress tolerance and life-history traits will tend to be genetically correlated; in Drosophila correlations with life-history traits other than longevity will tend to be negative. These predictions were tested by artificially selecting for increased desiccation tolerance in Drosophila melanogaster, using an 85% mortality level. The response to selection was rapid and the mean realized heritability was c. 0.65. The selection response was associated with a decreased rate of water loss, reduced activity and a decrease in metabolic rate in agreement with prediction (1). Selection did not alter body size. Selected lines were relatively more tolerant of starvation and a toxic concentration of ethanol in agreement with prediction (2), and had lower fecundities in agreement with prediction (3).