Globins are globular heme-binding proteins that are widely distributed throughout life. Globin

diversity is exceptional in nematodes and in the C. elegans genome 33 globin genes were

discovered. Globin-3 attracted our attention as it is one of the few globins that gives a clear

phenotype upon knockout: sterility. This globin is expressed in 20 to 30 neurons and in a specific

region in the somatic gonad. It is expressed as two isoforms, predicted to be membrane-bound: one

in the plasma membrane and one in the mitochondria. In this project, we will functionally

characterize these two GLB-3 isoforms. After exact localization inside the worm, we will study how

gonadal GLB-3 influences fertility and whether the neuronal GLB-3 affects worm behavior, with

focus on oxygen and temperature sensing. To understand its full function in neurons and the gonad,

we will also study electron transfer and ligand binding capacity of this globin. This will teil us

whether it works via oxygen binding or by redox reactions inside the cell. Also putative enzymatic

functions of GLB-3 will be tested. As it is very likely that this protein does not act solitary, we will

search for its interaction partners, with special focus on superoxide dismutases. With this research

strategy, we aim to understand the detailed biochemistry and function of GLB-3 in C. elegans. We

also hope to further establish C. elegans as a perfect model for uncovering the wide functional

diversity of globins.