RAB32 is a member of the small GTPase superfamily. RAB32 controls ER calcium management and disturbs the specific enhancement of calnexin on the MAM （mitochondria-associated membrane）， however avoids affecting the ER distribution of protein-disulfide isomerase and mitofusin-2. Furthermore， RAB32 regulates the targeting of PKA （cAMP-dependent protein kinase） to mitochondrial and ER membranes and by inactivation or overexpression enhances the phosphorylation of Drp1 and Bad. Using a combination of its functions as a regulator of MAM properties and a PKA-anchoring protein， the activity and expression level of RAB32 define the speed of apoptosis onset.
