| TCID | Name | Domain | Kingdom/Phylum | Protein(s) |
|---|---|---|---|---|
|
1.R.1.1.1 | Membrane Contact Site (MCS). Functions include lipid and ion transport between organelles as well as organelle positioning and division (Wu et al. 2018). | Eukaryota |
Metazoa, Chordata | Membrane contact site (MCS) of Homo sapiens |
|
1.R.1.1.2 | ATPase family AAA domain-containing protein 1 isoform 1, Msp1 or ATAD1, is a P5A-ATPase of 361 aas and 1 N-terminal TMS. It is a conserved eukaryotic AAA+ ATPase localized to the outer mitochondrial membrane, where it may extract mislocalized tail-anchored proteins (McKenna et al. 2020). Msp1's ATPase activity depends on its hexameric state. Castanzo et al. 2020 showed that Msp1 is a robust bidirectional protein translocase that is able to unfold diverse substrates by processive threading through its central pore. This unfoldase activity is inhibited by Pex3, a membrane protein proposed to regulate Msp1 at the peroxisome surface (Castanzo et al. 2020). This P5A-ATPase belongs to a eukaryotic-specific subfamily of P-type ATPases with previously unknown substrate specificity (McKenna et al. 2020). It interacts directly with mitochondrial tail-anchored proteins (McKenna et al. 2020). Msp1 (ATAD1 in mammals, also referred to as Thorase), can be found in the outer mitochondrial membrane and in peroxysomes as well as the ER (Dederer and Lemberg 2021). Structures of Spf1 (TC# 3.A.3.10.3) and this dismutase reveal how they remove mislocalized TA proteins from the ER and outer mitochondrial membranes, respectively (Sinning and McDowell 2022). | Eukaryota |
Metazoa, Chordata | Msp1 of Homo sapiens |
|
1.R.1.1.3 | Outer mitochondrial transmembrane helix translocase, MSP1, of 362 aas and 1 N-terminal TMS. It is required to remove mislocalized tail-anchored transmembrane proteins in mitochondria (Li et al. 2019; Matsumoto et al. 2019). Its structure indicates how this is accomplished (Sinning and McDowell 2022; McDowell et al. 2023McDowell et al. 2023). | Eukaryota |
Fungi, Ascomycota | MSP1 of Saccharomyces cerevisiae |
|
1.R.1.1.4 | Atad3 of Symbiodinium natans of 870 aas and up to 5 TMSs, about equally spaced throughout the length of the protein. ATPase family AAA domain containing protein 3, commonly known as ATAD3, is a versatile mitochondrial protein that is involved in a large number of pathways. ATAD3 is a transmembrane protein that spans both the inner mitochondrial membrane and outer mitochondrial membrane. It, therefore, functions as a connecting link between the mitochondrial lumen and the endoplasmic reticulum, facilitating their cross-talk. ATAD3 contains an N-terminal domain which is amphipathic in nature and is inserted into the membranous space of the mitochondria, while the C-terminal domain is present towards the lumen of the mitochondria and contains the ATPase domain. ATAD3 is known to be involved in mitochondrial biogenesis, cholesterol transport, hormone synthesis, apoptosis and several other pathways. It has also been implicated to be involved in cancer and many neurological disorders making it an interesting target for extensive studies. Goel and Kumar 2024 provided an updated comprehensive account of the role of ATAD3 in the mitochondria especially in lipid transport, mitochondrial-endoplasmic reticulum interactions, cancer and inhibition of mitophagy. | Eukaryota |
ATAD3 of Symbiodinium natans | |
|
1.R.1.1.5 | ATAD3 of Homo sapiens of 648 aas and possibly 2 TMS at residue 250 and at the C-terminus of the protein. | Eukaryota |
Metazoa, Chordata | ATAD3 of Homo sapiens |