TCDB is operated by the Saier Lab Bioinformatics Group
TCIDNameDomainKingdom/PhylumProtein(s)
1.A.87.1.1









Plant Ca2+ channel protein, Mid1 complementary activity 1, MCA1 (Iida et al. 2013).  MCA1 and MCA2 each forms a homotetramer and exhibit Ca2+-permeable mechanosensitive channel activity.  Both are single-pass type I transmembrane proteins with their N-termini located extracellularly and their C-termini located intracellularly. An EF hand-like motif, coiled-coil motif, and Plac8 motif may all be in the cytoplasm, suggesting that the activities of both channels can be regulated by intracellular Ca2+ and protein interactions (Kamano et al. 2015). However, hydropathy plots suggest that the Plac8 domain may be transmembrane with 3 TMSs.  mca1 but not mca2 mutants show defects in root entry into hard agar, whereas mca2 but not mca1 mutants are defective in Ca2+ uptake in A. thaliana roots (Hamilton et al. 2015). Root growth reduction in response to mechanical stress involves MCA1 tgether with WDL5 (Q94C48) subject to ethylene-mediated regulation) and the co-receptor BAK1 (Q94F62) (Okamoto et al. 2021).

 

Eukaryota
Viridiplantae, Streptophyta
MCA1 of Arabidopsis thaliana
1.A.87.1.2









Plant Ca2+ channel protein, Mid1 complementary activity 2, MCA2 (Iida et al. 2013).  Catalyzes mechanical stress-induced Ca2+ influx.  It is tetrameric with a small transmembrane domain and a large cytoplasmic domain (Shigematsu et al. 2014).  MCA1 and MCA2 both have their N-termini located extracellularly and their C-termini located intracellularly. An EF hand-like motif, coiled-coil motif, and Plac8 motif may all be in the cytoplasm, suggesting that the activities of both channels can be regulated by intracellular Ca2+ and protein interactions (Kamano et al. 2015). However hydropathy plots suggest that the Plac8 domain may be transmembrane with 3 TMSs.  mca1 but not mca2 mutants show defects in root entry into hard agar, whereas mca2 but not mca1 mutants are defective in Ca2+ uptake in A. thaliana roots (Hamilton et al. 2015).

Eukaryota
Viridiplantae, Streptophyta
MCA2 of Arabidopsis thaliana
1.A.87.1.3









MCA1 isoform X2 of 377 aas with one N-terminal TMS and possibly 3 or 4 C-terminal TMSs.

Eukaryota
Viridiplantae, Streptophyta
MCA1 of Solanum pennellii (Lycopersicon pennellii)
1.A.87.1.4









PLAC8 family protein of 385 aas with MID1-complementing activity.

Eukaryota
Viridiplantae, Streptophyta
PLAC8 family protein of Theobroma cacao
1.A.87.1.5









Mid1 complementing activity 1 of 154 aa

Eukaryota
Viridiplantae, Streptophyta
MCA1 of Vigna radiata
1.A.87.2.1









Receptor protein kinase of 567 aas.  The first 140 aas are homologous to the N-terminal domains of MCA1 and 2; residues 240 - 430 are homologous to ser/thr protein kinases of 9.A.15.1.1, 9.B.45.1.3 and 9.B.106.3.1.

Eukaryota
Viridiplantae, Streptophyta
Receptor protein kinase of Zea mays
1.A.87.2.2









Protein kinase domain protein of 522 aas.

Eukaryota
Viridiplantae, Streptophyta
PKD protein of Oryza sativa
1.A.87.2.3









Receptor for extracellular ATP which functions in plant growth, development and stress responses; lectin receptor kinase 1.9; DORN1.  Binds ATP with high affinity (46nM) and is required ofr ATP-induced calcium response, mitogen-activated protein kinase activation and normal gene expression (Choi et al. 2014).

Eukaryota
Viridiplantae, Streptophyta
DORN1 of Arabidopsis thaliana
1.A.87.2.4









GHR1 (GUARD CELL HYDROGEN PEROXIDE-RESISTANT 1) transmembrane receptor-like protein of 1053 aas and 1 - 3 TMSs.  Regulates the SLAC1 protein (2.A.16.5.1) (Wang et al. 2017). The C-terminus shows extensive sequence similarity with members of this family, but the N-terminus shows similarity with members of family 3.A.20 (Leucine repeat proteins).

Eukaryota
Viridiplantae, Streptophyta
GHR1 of Arabidopsis thaliana
1.A.87.2.5









Uncharacterized protein with an ATP binding domain of 629 aas and 2 TMSs.

Eukaryota
Viridiplantae, Streptophyta
UP of Arabidopsis thaliana
1.A.87.2.6









Protein BRASSINOSTEROID INSENSITIVE 1, BRI1, of 1196 aas and 2 or 3 TMSs. Receptor with kinase activity acting on both serine/threonine- and tyrosine-containing substrates. In response to brassinosteroid binding, it regulates a signaling cascade involved in plant development, including expression of light- and stress-regulated genes, promotion of cell elongation, normal leaf and chloroplast senescence, and flowering. It binds brassinolide, and less effectively, castasterone (Oh et al. 2009).

Eukaryota
Viridiplantae, Streptophyta
BRI1 of Arabidopsis thaliana
1.A.87.2.9









The phytosulfokine receptor, PSKR1, of 1008 aas with both a serine/threonine-protein kinase activity and a guanylate cyclase activity (Kwezi et al. 2011). In response to phytosulfokine binding, it activates a signaling cascade involved in plant cell differentiation, organogenesis, somatic embryogenesis, cellular proliferation and plant growth. It is also involved in plant immunity, with antagonistic effects on bacterial and fungal resistances (Mosher et al. 2013). CNGC17 and AHAs form a functional cation-translocating unit that is activated by PSKR1/BAK1 and possibly other BAK1/RLK complexes (Ladwig et al. 2015). PSKR is a transmembrane LRR-RLK family protein with a binding site for the small signalling peptide, phytosulfokine (PSK). There are 15 members in rice (Orysa sativa), induced under different conditions in different plant tissues  (Nagar et al. 2020). PSKR1 and PSYR1 mediate a signaling pathway in response to two distinct ligands, which redundantly contribute to cellular proliferation and plant growth (Amano et al. 2007).

Eukaryota
Viridiplantae, Streptophyta
PSKR1 of Arabidopsis thaliana (Mouse-ear cress)
1.A.87.2.10









Uncharacterized leucine-rich repeat domain-containing proteins of 387 aas and putative protein kinase of 399 aas, respectively, each with one TMS, the first of these proteins at the N-terminus, and the second near its C-terminus. These two proteins are most similar to different parts of the other proteins in TC subclass # 1.A.87.2.

Bacteria
Thermodesulfobacteriota
UPs of Desulfosarcina alkanivorans
1.A.87.2.11









Leucine-rich repeat (LRR) receptor-like serine/threonine-protein kinase, ERECTA, of 966 aas and 2 TMSs, one at the N-terminus of the protein, and one at residues 580 - 600.  Oterh peaks of hydrophobicity may also be transmembrane. It is a receptor kinase that, together with ERL1 and ERL2, regulates aerial architecture, including inflorescence (e.g. shoot apical meristem-originating organ shape, elongation of the internode and pedicels, and adaxial-abaxial polarity), and stomatal patterning (e.g. density and clustering), probably by tuning cell division and expansion. It regulates canalization as well as cell wall composition and structure, and it confers resistance to the pathogenic bacteria Ralstonia solanacearum and to the necrotrophic fungi Plectosphaerella cucumerina and Pythium irregulare. It is required for callose deposition upon infection. (Torii et al. 1996).

Eukaryota
Viridiplantae, Streptophyta
ERL2 of Arabidopsis thaliana
1.A.87.2.12









Receptor-like kinase 1, RKL1, of 655 aas and 2 TMSs, one N-terminal and one centrally located. These receptor-like kinases directly regulate the functions of membrane transport proteins in plants (Li et al. 2022).

Eukaryota
Viridiplantae, Streptophyta
RKL1 of Arabidopsis thaliana
1.A.87.2.13









Transmembrane kinase receptor of 942 aas and 2 TMSs, one at the N-terminus of the protein and the second at residue 490 (Chang et al. 1992). It phosphorylates only serine and threonine residues (Schaller and Bleecker 1993) and is involved in auxin signal transduction and cell expansion as well as proliferation regulation (Dai et al. 2013). With ABP1, it is a cell surface auxin perception complex that activates ROP signaling pathways (Xu et al. 2014). It is required for auxin promotion of pavement cell interdigitation and promotes the formation of the ABP1-TMK1 protein complex (Xu et al. 2014).

Eukaryota
Viridiplantae, Streptophyta
TMK1 of Arabidoopsis thaliana
1.A.87.2.14









Nod-factor receptor 1a, NFR1, of 621 aas and about 6 TMSs in an estimated 2 + 1 + 1 + 1 + 1 TMS topology. This protein plus NFR5 constitutes the Lotus japonicus core receptor complex in root nodule symbiosis that initiates the cortical root nodule organogenesis program (Rübsam et al. 2023).

Eukaryota
Viridiplantae, Streptophyta
NFR1 of Lotus japonicus
1.A.87.2.15









Nod-factor receptor 5, NFR5, of 595 aas and about possibly 3 TMSs, one at the N-terminus, one at residue 250, and one at residue 470. This protein plus NFR1 (TC# 1.A.87.2.14) constitutes the Lotus japonicus core receptor complex in root nodule symbiosis that initiates the cortical root nodule organogenesis program (Rübsam et al. 2023).

 

Eukaryota
Viridiplantae, Streptophyta
NFR5 of Lotus japonicus
1.A.87.2.16









G-type lectin S-receptor-like serine/threonine-protein kinase, SRK, of 853 aas with possibly 4 TMSs, one at the N-terminus of the protein, and 3 more at residues 450, 580 and 710 (Zhou et al. 2023).

Eukaryota
Viridiplantae, Streptophyta
SRK of Arabidopsis thaliana
1.A.87.2.17









Pseudokinase (serine/threonine protein kinase), ZRK1, of 351 aas and 2 strongly hydrophobic TMSs (at residues 130 and 260) (Bi et al. 2021).

Eukaryota
Viridiplantae, Streptophyta
ZRK1 of Arabidopsis thaliana
1.A.87.2.18









The ZAR1-RKS1-PBL2UMP complex which transports cations including Ca2+ (Bi et al. 2021).The cations transported include Na+, K+, Cs+, Mg2+ and Ca2+. All three proteins included in this complex are homologous to the proteins in TC family 1.A.87.

Eukaryota
Viridiplantae, Streptophyta
The ZAR1-RKS1-PBL2UMP complex of Arabidopsis thaliana: ZAR1 of 716 aas (Q9ZU46)
RKS1 of 833 aas (Q9ZT07)
PBL2UMP of 426 aas (O49839)
1.A.87.2.19









Probable LRR receptor-like serine/threonine-protein kinase IRK of 964 aas and 2 or 3 TMSs, one at the N-terminus, one large peak at ~residues 610 - 640, and possibly one at the C-terminus of the protein. Distinct ADP-ribosylation factor-GTP exchange factors govern the opposite polarity of two receptor kinases, one of which is IRK, and the other is K0IN (Rodriguez-Furlan et al. 2023).

Eukaryota
Viridiplantae, Streptophyta
IRK of Arabidopsis thaliana
1.A.87.2.20









Cysteine-rich receptor-like (ser/thr) protein kinase 17, CRK17, of 686 aas and two TMSs, one at the N-terminus and one at residue 310. 

Eukaryota
Viridiplantae, Streptophyta
CRK17 of Arabidopsis thaliana
1.A.87.3.1









Plant cadmium resistance, PCR, protein of 164 aas.  It shows homology to the C-terminal PLAC8 domain of MCA1 and 2.  Strontium alleviates the growth inhibition and toxicity caused by cadmium in rice seedlings (Liu et al. 2023).

Eukaryota
Viridiplantae, Streptophyta
Cadmium resistance protein of Solanum lycopersicum (Tomato) (Lycopersicon esculentum)
1.A.87.3.2









Plant Cadmium Resistance (PCR) protein. This protein corresponds to the C-terminal PLAC8 domain of MCA1 (TC# 1.A.87.1.1) (Song et al., 2011). The plant cadmium resistance (PCR) gene family has been characterized in Brassica napus and one member, has been functionally analyzed: BnPCR10.1 is involved in cadmium and copper tolerance( (Liu et al. 2023).

Eukaryota
Viridiplantae, Streptophyta
PLAC8 family protein of Arabidopsis thaliana
1.A.87.3.3









Sea squirt membrane protein of 110 aas

Eukaryota
Metazoa, Chordata
Membrane protein of Ciona intestinalis
1.A.87.3.4









Uncharacterized protein of 161 aas

Eukaryota
Viridiplantae, Streptophyta
UP of Capsella rubella
1.A.87.3.5









Plant cadmium resistance 6 protein, CadR6, of 224 aas.

Eukaryota
Viridiplantae, Streptophyta
CadR6 of Arabidopsis thaliana
1.A.87.3.6









Uncharacterized protein of 186 aas

Eukaryota
Viridiplantae, Streptophyta
UP of Glycine max
1.A.87.3.7









Plant cadmium resistance 1 protein of 151 aas and 2 TMSs. PCR1.  Involved in glutathione-independent cadmium resistance. Reduces cadmium uptake rather than activating efflux, but is not closely coupled to calcium transport (Song et al. 2011).

Eukaryota
Viridiplantae, Streptophyta
PCR1 of Arabidopsis thaliana
1.A.87.3.8









Plant cadmium resistance 2 (PCR2) protein.  Zinc ion exporter (Song et al. 2010; Song et al. 2011).  Involved in glutathione-independent cadmium resistance. Reduces cadmium uptake rather than activating efflux, but is not closely coupled to calcium transport.

Eukaryota
Viridiplantae, Streptophyta
PCR2 of Arabidopsis thaliana
1.A.87.3.9









FW2.2-like (FWL) protein of 180 aas and 2 or 3 TMSs.  It is involved in plant and fruit development, and possibly in calcium transport (Libault and Stacey 2010). See family description for details about its possible functions in the tomato (Beauchet et al. 2021).

Eukaryota
Viridiplantae, Streptophyta
FWL of Persea americanan (Avocado)
1.A.87.3.10









Fruit-weight 2.2 protein of 197 aas and 3 TMSs.  May be involved in Cd2+ resistance as well as  translocation of Cd2+ from roots to shoots (Xiong et al. 2018). May form homooligomeric structures in the membrane.

Eukaryota
Viridiplantae, Streptophyta
FWL protein of Medicago truncatula (Barrel medic) (Medicago tribuloides)
1.A.87.3.11









Fruit-weight 2.2 protein of 161 aas and 4 TMSs.  May be involved in Cd2+ resistance as well as  translocation of Cd2+ from roots to shoots (Xiong et al. 2018).  May form homooligomeric structures in the membrane.

Eukaryota
Viridiplantae, Streptophyta
FWL protein of Medicago truncatula (Barrel medic) (Medicago tribuloides)
1.A.87.3.12









Fruit Weight 2.2 (FW2.2) protein of 163 aas and possibly 3 TMSs. See family description for details (Beauchet et al. 2021).

 

Eukaryota
Viridiplantae, Streptophyta
FW2.2 of Solanum lycopersicum (Tomato) (Lycopersicon esculentum)
1.A.87.3.13









Protein PLANT CADMIUM RESISTANCE 10 of 190 aas and 2 (or 3) TMSs. It transports (expels) cadmium, lead and aluminum ions, thereby protecting the plant from these toxic cations for more appreciable growth (Guan et al. 2023).

Eukaryota
Viridiplantae, Streptophyta
Cadmium resistance 10 protein of Populus euphratica (Euphrates poplar)
1.A.87.4.1









Ubiquitin protein ligase with the first 250 aas homologous to MCA2.

Eukaryota
Viridiplantae
Ubiquitin ligase of Physcomitrella patens
1.A.87.4.2









U box containing protein 15

Eukaryota
Viridiplantae, Streptophyta
U box protein of Solanum lycopersicum (Tomato) (Lycopersicon esculentum)
1.A.87.5.1









Protein kinase_Tyr of 657 aas with N-terminal domain similar to that of MCA1, with N-terminal TMS containing a conserved aspartyl residue.

Eukaryota
Fungi, Basidiomycota
PKinase-Tyr of Phanerochaete carnosa