. Author manuscript; available in PMC: 2010 Oct 1.

Published in final edited form as: Int J Biochem Cell Biol. 2009 Apr 21;41(10):1817–1827. doi: 10.1016/j.biocel.2009.04.010

Table 2.

Summary of cited proteins involved in ER-Mitochondria functional link

SYMBOL	FULL NAME	DETAILS
*ER and Mitochondria functional link: MAM*
FACL4	Long-chain fatty acid-CoA ligase type 4	Key enzyme involved in the metabolism of arachidonic acid, eicosapentaenoic acid, and docosahexaenoic acid, and thereby plays a key role in lipid biosynthesis and fatty acid degradation. FACL4 preferentially utilizes arachidonate as substrate and selectively esterifies it with coenzyme A, forming acyl-CoA, which can then be incorporated into membrane phospholipid
grp75	glucose-regulated protein 75	Molecular chaperone which regulate the association between ER and mitochondria: cytosolic grp75 links IP3Rs to VDAC at the OMM, the resulting association presumably enhances the Ca²⁺ accumulation in mitochondria by stabilizing conformations or the coupling of the two receptors
IP₃Rs	Inositol-1,4,5-trisphosphate receptors	See Table 1
GRP78/BiP	78-kDa glucose-regulated protein GRP78, also referred to as the immunoglobulin binding protein BiP	Central regulator of ER functions due to its roles in protein folding and assembly, targeting misfolded protein for degradation, ER Ca²⁺-binding and controlling the activation of trans-membrane ER stress sensors
PACS-2	Phosphofurin acidic cluster sorting protein 2	Multifunctional sorting protein that integrates ER-mitochondria communication, ER homeostasis, homeostasis of ER Ca²⁺ and apoptosis. PACS-2 controls the apposition of mitochondria with the ER and formation of ER lipid-synthesizing centers found on MAM, and regulates the distribution and activity of calnexin
PSS-1	Phosphatidylserine synthase-1	Enzyme involved in phosphatidylserine biosynthesis in mammalian cells: exchanges serine for choline of phosphatidylcholine; PSS-1 is highly enriched in MAM and is largely excluded from the bulk of the ER
Sig-1R	Sigma-1 receptor	Ca²⁺-sensitive and ligand-operated receptor chaperone that specifically targets MAM. Sig-1Rs form a Ca²⁺-sensitive chaperone machinery with BiP and prolong Ca²⁺ signaling from ER into mitochondria by stabilizing IP₃R-3 at MAM; Sig-1Rs can translocate under chronic ER stress
VDAC	Voltage dependent anion channel	See Table 1