The small GTPase Rab5 has been proposed to be a master regulator of endosome biogenesis; using in vivo RNA interference and mathematical modelling it is shown here that the endolysosomal system is resilient to loss of Rab5 until its concentration drops below a critical level, at which point endosomes are lost, leading to increased serum low-density lipoprotein levels, alterations in metabolism and hepatocellular polarity.
- Anja Zeigerer
- Jerome Gilleron
- Marino Zerial