TCDB is operated by the Saier Lab Bioinformatics Group
TCIDNameDomainKingdom/PhylumProtein(s)
*2.A.43.1.1









Lysosomal cystine transporter, cystinosin of 267 aas and 7 TMSs. It uses a cystine:H+ symport mechanism. H+ binds to an aspartate residue in one of the two PQ-loops (Ruivo et al., 2012). Several mutations in the CTNS gene gives rise to ocular cystinosis (Browning et al. 2019). Microvesicle delivery of cystinosin to ex vivo corneal keratocytes (corneal fibroblasts) corrects the cystine transport defect and prevents the accumulation of lysosomal cystine (Thoene et al. 2020).

Eukaryota
Metazoa
Cystinosin or CTNS of Homo sapiens
*2.A.43.1.2









Cystinosin homolog
Eukaryota
Metazoa
CG17119 of Drosophila melanogaster
*2.A.43.1.3









The ERD-1 suppressor, ERS1

Eukaryota
Fungi
ERS1 of Saccharomyces cerevisiae (P17261)
*2.A.43.1.4









Cystinosin homolog
Eukaryota
Viridiplantae
At5g40670 of Arabidopsis thaliana
*2.A.43.2.1









The lysosomal lysine-arginine transporter, LAAT1 or PQ-loop repeat containing protein 2 (PQLC2) (291aas; 7 TMSs). Also transports the mixed disulfide of cysteine-cysteamine, a lysine analogue, as well as canavanine, a toxic arginine analogue. Cysteamine is used in the treatment of cystinosis (Liu et al., 2012; Jézégou et al. 2012).

Eukaryota
Metazoa
PQLC2 of Homo sapiens (Q6ZP29)
*2.A.43.2.2









The lysosomal lysine-arginine transporter, LAAT1, PQ-loop superfamily member (qx42 gene product; 310aas; 7 TMSs) (Liu et al., 2012).

Eukaryota
Metazoa
LAAT1 of Caenorhabditis elegans (Q95XZ6)
*2.A.43.2.3









Vacuolar (lysosomal) cationic amino acid transporter (YOL092W) (308aas; 7 TMSs), LAAT1.  Involved in cationic amino acid homeostasis (Jézégou et al. 2012).

Eukaryota
Fungi
LAAT1 of Saccharomyces cerevisiae (Q12010)
*2.A.43.2.4









PQ-loop repeat protein (320aas; 7 TMSs)

Eukaryota
Entamoeba
PQLR protein Entamoeba histolyticus (C4LT11)
*2.A.43.2.5









PQ-loop repeat protein (288aas; 7 TMSs)

Eukaryota
Viridiplantae
 PQLR protein of Arabidopsis thaliana (O49437)
*2.A.43.2.6









7 TMS protein 1 (319aas; 7 TMSs)

Eukaryota
Hexamitidae
7 TMS protein of Giardia lamblia (E1F7I8)
*2.A.43.2.7









Probable vacuolar (lysosomal) cationic amino acid exporter, RTC2 (Ypq3; Ybr147). Involved in amino acid homeostasis. Up-regulated by addition of ammonia or amino acids to a nitrogen-depleted medium (Jézégou et al. 2012). Resistant to fluconazole. Increased resistance to caspofungin. Suppresses CDC13-1 temperature sensitivity.

Eukaryota
Fungi
RTC2 of Saccharomyces cerevisiae
*2.A.43.2.8









Vacuolar (lysosomal) putative cationic amino acid exporter, Ypq2 (Ydr352); involved with cationic amino acid homeostasis (Jézégou et al. 2012).

Eukaryota
Fungi
Ypq2 of Saccharomyces cerevisiae
*2.A.43.2.9









PQ loop protein of 384 aas and 7 (3 + 4) TMSs

Eukaryota
Viridiplantae
PQ-loop protein of Populus trichcarpa
*2.A.43.2.10









The probable vacuolar amino acid transporter YPQ1 of 381 aas and 6 TMSs.

Eukaryota
Viridiplantae
Ypq1 of Sesamum indicum
*2.A.43.2.11









The probable vacuolar amino acid transporter Ypq1 of 381 aas and 6 TMSs

Eukaryota
Viridiplantae
Ypq1 of Gossypium raimondii].
*2.A.43.2.12









Uncharacterized protein of 282 aas and 7 (3 + 4) TMSs.

Eukaryota
Viridiplantae
UP of Gossypium raimondii
*2.A.43.2.13









Cdc50 supressor, CSF1 of 405 aas and 7 TMSs.  Appears to function as a phospholipid flippase or to regulate PL flipping in endosomes or late golgi vesicles (Yamamoto et al. 2017).

Eukaryota
Fungi
CSF1 of Saccharomyces cerevisiae
*2.A.43.2.14









Uncharacterized PQ loop repeat protein of 228 aas and 6 TMSs.

Eukaryota
Entamoebidae
UP of Entamoeba histolytica
*2.A.43.3.1









The Lec15/Lec35 suppressor, SL15
Eukaryota
Metazoa
SL15 of Cricetulus griseus
*2.A.43.3.2









PQ-loop-containing protein 3 (PQLC3)

Eukaryota
Metazoa
PQLC3 of Mus musculus (Q8C6U2)
*2.A.43.4.1









Uncharacterized protein C4C5.03
Eukaryota
Fungi
SPAC4C5.03 of Schizosaccharomyces pombe
*2.A.43.4.2









Uncharacteerized protein of 308 aas and 7 TMSs.

Eukaryota
Entamoebidae
UP of Entamoeba histolytica
*2.A.43.4.3









Uncharacterized protein of 363 aas and 8 TMSs.

Eukaryota
Entamoebidae
UP of Entamoeba histolytica