Biology subjects

Busto, J. V.

Publications and source records attributed to Busto, J. V..

2 recordsLinked to original sources

bioRxiv2023

Role of the small protein Mco6 in the mitochondrial sorting and assembly machinery

The majority of mitochondrial precursor proteins are imported through the Tom40 {beta}-barrel channel of the translocase of the outer membrane (TOM). The sorting and assembly machinery (SAM) is essential for {beta}-barrel membrane protein insertion into the outer membrane and thus required for the assembly of the TOM complex. Here we demonstrate that the a-helical outer membrane protein Mco6 forms a complex with the mitochondrial distribution and morphology protein Mdm10 as part of the SAM machinery. Moreover, Mco6 also interacts with the subunit Mim1 of the mitochondrial import complex (MIM), which is itself required for the biogenesis of a-helical outer membrane proteins. MCO6 and MDM10 display a negative genetic interaction and a MCO6-MDM10 yeast double mutant contains reduced levels of TOM complex. Cells lacking Mco6 affect the levels of Mdm10 and MIM-subunits associated with assembly defects of the TOM complex. Thus, this work reveals a role of the SAMMco6 complex for the biogenesis of the mitochondrial outer membrane.

cell biology↗

bioRxiv2018

Lateral plasma membrane compartmentalization links protein function and turnover

Biological membranes organize their proteins and lipids into nano- and microscale patterns. In the yeast plasma membrane (PM) constituents segregate into a large number of distinct domains. However, if and how this intricate patchwork contributes to biological functions at the PM is still poorly understood. Here, we reveal an elaborate interplay between PM compartmentalization, biochemical function and endocytic turnover. Using the methionine permease Mup1 as model system we demonstrate that this transporter segregates into PM clusters. Clustering requires sphingolipids, the tetraspanner Nce102 and TORC2 signaling. Importantly, we show that during substrate transport, a simple conformational change in Mup1 mediates rapid relocation into a unique disperse network at the PM. Clustered Mup1 is protected from turnover, whereas relocated Mup1 actively recruits the endocytic machinery thereby initiating its own turnover. Our findings suggest that lateral compartmentalization provides an important regulatory link between function and turnover of PM proteins.

cell biology↗