TCDB is operated by the Saier Lab Bioinformatics Group
TCIDNameDomainKingdom/PhylumProtein(s)
*1.A.50.1.1









Phospholamban (PLB) pentameric Ca2+/K+ channel (Kovacs et al., 1988; Smeazzetto et al. 2013; Smeazzetto et al. 2014).  In spite of extensive experimental evidence, suggesting a pore size of 2.2 Å, the conclusion of ion channel activity for phospholamban has been questioned (Maffeo and Aksimentiev 2009).

Eukaryota
Metazoa
PLB of Homo sapiens (P26678)
*1.A.50.1.2









Cardiac phospholamban-like protein of 131 aas and 1 TMS.

Eukaryota
Metazoa
Phospholamban of Scleropages formosus
*1.A.50.1.3









Cardiac phospholamban of 55 aas and 1 TMS.

Eukaryota
Metazoa
Phospholamban of Esox lucius (northern pike)
*1.A.50.2.1









Sarcolipin (SLN). Oligomeric interactions of sarcolipin and the Ca-ATPase have been documented (Autry et al., 2011).  Sarcolipin, but not phospholamban, promotes uncoupling of the SERCA pump (3.A.3.2.7; Sahoo et al. 2013).  Forms a pentameric pore that can transport water, Na+, Ca2+ and Cl-.  Leu21 serves as the gate (Cao et al. 2015).   In the channel, water molecules near the Leu21 pore demonstrated a clear hydrated-dehydrated transition (Cao et al. 2016). Small ankyrin 1 (sAnk1; TC#8.A.28.1.2) and SLN interact with each other in their transmembrane domains to regulate SERCA (TC# 3.A.3.2.7) (Desmond et al. 2017).

Eukaryota
Metazoa
SLN of Homo sapiens (O00631)
*1.A.50.2.2









sarcolipin-like protein of 32 aas and 1 TMS.

Eukaryota
Metazoa
Sarcolipin of Esox lucius (northern pike)
*1.A.50.2.3









Sarcolipin-like protein (SLN) of 31 aas and 1 TMS

Eukaryota
Metazoa
SLN of Ovis aries (Sheep)
*1.A.50.3.1









Myoregulin of 46 aas (Anderson et al. 2015).

Eukaryota
Metazoa
Myoregulin of Homo sapiens
*1.A.50.3.2









Myoregulin of 43 aas

Eukaryota
Metazoa
Myoregulin of Echinops telfairi
*1.A.50.3.3









Myoregulin of 105 aas

Eukaryota
Metazoa
Myoregulin of Sarcophilus harrisii (Tasmanian devil) (Sarcophilus laniarius)
*1.A.50.4.1









DWORF of 34 aas; synthetic construct (Nelson et al. 2016).  Counteracts the inhibitory effects of single transmembrane peptides, phospholamban (TC# 1.A.50.1), sarcolipin (1.A.50.2) and myoregulin (1.A.50.3), on SERCA (TC# 3.A.3.2).  Homology with the inhibitory peptides has not been established although all of these peptides have about the same size with a single C-terminal TMS. 

DWORF, made synthetically, probably copied from DWORF of Mus musculus
*1.A.50.5.1









Endoregulin, ELN, also called small integral membrane protein-6, SMIM6, is of 62 aas and 1 TMS.  This protein and the other members of the phospholamban family have been designated "micropeptides". Micropeptides function as regulators of calcium-dependent signaling in muscle. The sarco/endoplasmic reticulum Ca2+ ATPase (SERCA TC# 3.A.3.2.7), is the membrane pump that promotes muscle relaxation by taking up Ca2+ into the sarcoplasmic reticulum. It is directly inhibited by three known muscle-specific micropeptides: myoregulin (MLN), phospholamban (PLN) and sarcolipin (SLN). In non muscle cells, there are two other such micopeptides, endoregulin (ELN) and "another-regulin (ALN) (Anderson et al. 2016).  Endoregulin is also known as "small integral membrane protein-6" (SMIM6) while ALN is also known as Protein C4 orf3 (C4orf3).  These proteins share key amino acids with their muscle-specific counterparts and function as direct inhibitors of SERCA pump activity. The distribution of transcripts encoding ELN and ALN mirrored that of SERCA isoform-encoding transcripts in nonmuscle cell types. Thus, these two proteins are additional members of the SERCA-inhibitory micropeptide family, revealing a conserved mechanism for the control of intracellular Ca2+ dynamics in both muscle and nonmuscle cell types (Anderson et al. 2016).

Eukaryota
Metazoa
Endoregulin of Homo sapiens
*1.A.50.5.2









ELN homologue of 78 aas and 1 TMS.

Eukaryota
Metazoa
ELN homologue of Nothobranchius furzeri
*1.A.50.5.3









ELN homologue of 75 aas and 1 TMS.

Eukaryota
Metazoa
ELN of Larimichthys crocea (large yellow croaker)
*1.A.50.5.4









Bacterial ELN homologue of unknown function with 101 aas and 1 TMS

Bacteria
Proteobacteria
ELN homologue of Desulfobacteraceae bacterium
*1.A.50.5.5









ELN homologue of 85 aas and 1 TMS

Bacteria
Thermotogae
ELN homologue of Thermotoga sp.
*1.A.50.6.1









"Another-regulin", ALN, of 66 aas and 1 TMS.  Also called Protein C4orf3. This protein and the other members of the phospholamban family have been designated "micropeptides". Micropeptides function as regulators of calcium-dependent signaling in muscle. The sarco/endoplasmic reticulum Ca2+ ATPase (SERCA, TC# 3.A.3.2.7), is the membrane pump that promotes muscle relaxation by taking up Ca2+ into the sarcoplasmic reticulum. It is directly inhibited by three known muscle-specific micropeptides: myoregulin (MLN), phospholamban (PLN) and sarcolipin (SLN). In non muscle cells, there are two other such micopeptides, endoregulin (ELN) and "another-regulin" (ALN) (Anderson et al. 2016). These proteins share key amino acids with their muscle-specific counterparts and function as direct inhibitors of SERCA pump activity. The distribution of transcripts encoding ELN and ALN mirror that of SERCA isoform-encoding transcripts in nonmuscle cell types. Thus, these two proteins are additional members of the SERCA-inhibitory micropeptide family, revealing a conserved mechanism for the control of intracellular Ca2+ dynamics in both muscle and nonmuscle cell types (Anderson et al. 2016).

Eukaryota
Metazoa
ALN in Homo sapiens
*1.A.50.6.2









Uncharacterized protein of 93 aas and 1 TMS.

Eukaryota
Metazoa
UP of Larimichthys crocea (large yellow croaker)
*1.A.50.6.3









Uncharacterized protein of 104 aas and 1 TMS

Eukaryota
Metazoa
UP of Xenopus laevis (African clawed frog)
*1.A.50.6.4









Uncharacterized C4orf3 homologue of77 aas and 1 TMS

Eukaryota
Metazoa
UP of Monodelphis domestica (Gray short-tailed opossum)