TCDB is operated by the Saier Lab Bioinformatics Group
TCIDNameDomainKingdom/PhylumProtein(s)
1.C.127.1.1









Human Apolipooprotein A1, APOL1, a tripanolytic factor of 398 aas and 4 possible α-helical TMSs in a 1 + 2 + 1 TMS arrangement. Pore-formation has been demonstrated in planar bilayer membranes. APOL1 inserts into such bilayers at acidic pH to form pH-gated non-selective cation channels that open upon pH neutralization. This corresponds to the pH changes encountered during endocytic-recycling, suggesting that APOL1 forms a cytotoxic cation channel in the parasite plasma membrane. Pore-formation is blocked by the serum resistance-associated VSG protein, SRA. See family discussion for a published description of this protein (Thomson and Finkelstein 2015). APOL1 risk variants induce opening of the mitochondrial permeability transition pore (Carney 2019). Cation channel conductance and pH gating of the innate immunity factor APOL1 is governed by pore lining residues in the C-terminal domain (Schaub et al. 2020). Two residues in the C-terminal domain (CTD), tyrosine-351 and glutamate-355 influence pH gating properties, and a single residue, aspartate-348, determines both cation selectivity and pH gating. Thus, the predicted transmembrane region closest to the APOL1 C-terminus is the pore-lining segment of this channel-forming protein (Schaub et al. 2020).

Eukaryota
Metazoa
APOL1 of Homo sapiens
1.C.127.1.2









Uncharacterized protein of 566 aas and 4 TMSs in a 1 + 2 + 1 TMS arrangement.

Eukaryota
Metazoa
UP of Takifugu rubripes (Torafugu)
1.C.127.1.3









Apolipoprotein L domain-containing protein 1 isoform X1 of 319 aas and 2 TM

Eukaryota
Metazoa
Apolipoprotein of Chrysemys picta bellii
1.C.127.1.4









Uncharacterized protein of 1010 aas and 4 TMSs in a 1 (N-terminal) + 2 + 1 TMS arrangement.

Eukaryota
Metazoa
UP of Tigriopus californicus (Marine copepod)
1.C.127.1.5









Uncharacterized protein of 313 aas and 3 TMSs in a 2 + 1 TMS arrangement.

Eukaryota
Metazoa
UP of Pygocentrus nattereri (red-bellied piranha)
1.C.127.1.6









Uncharacterized protein of 1075 aas and possibly 6 TMSs in a 1 (N-terminal) + 1 + 2 + 2 TMS arrangement.

Eukaryota
Metazoa
UP of Crassostrea virginica (eastern oyster)
1.C.127.1.7









Serine/threonine-protein kinase domain (N-terminus) and Lipoprotein domain (C-terminus) protein, Nek5, of 543 aas and 4 TMSs in a 2 + 2 TMS arrangement.

Eukaryota
Metazoa
Kinase of Danio rerio
1.C.127.1.8









Uncharacterized protein of 289 aas and 4 TMSs in a 2 + 2 TMS arrangement.

Eukaryota
Metazoa
UP of Acropora millepora (cnidaria)
1.C.127.2.1









Uncharacterized protein of 536 aas and 2 TMSs.  This bacterial protein shows sequence similarity to animal members of the family in the region showing the 2 TMSs.

Bacteria
Proteobacteria
UP of Helicobacter suis
1.C.127.2.2









Prolipoprotein of 553 aas and 0 TM

Viruses
Caudovirales
Lipoprotein of Helicobacter phage PtB89G
1.C.127.2.3









Uncharacterized protein of 700 aas and 1 - 3 TMSs, two of which may be adjacent to each other. This protein is annotated as a divalent metal ion transporter, but this is probably an error.

Bacteria
Proteobacteria
UP of Helicobacter canis