TCDB is operated by the Saier Lab Bioinformatics Group
TCIDNameDomainKingdom/PhylumProtein(s)
9.B.198.1.1









LAM1 (YSP1) of 1228 aas and 1 or more TMSs (Wong and Levine 2016).

Eukaryota
Fungi
LAM1 of Saccharomyces cerevisiae
9.B.198.1.2









LAM3 (SIP3) of 1229 aas and 1 or more TMSs.

Eukaryota
Fungi
LAM3 of Saccharomyces cerevisiae
9.B.198.1.3









SipA3 of 482 aas and 0 TMSs

Eukaryota
Fungi
SipA of Verticillium alfalfae (Verticillium wilt of alfalfa) (Verticillium albo-atrum)
9.B.198.1.4









Uncharacterized protein of 1363 aas and 1 or more TMSs

Eukaryota
Fungi
UP of Rhizophagus irregularis (Arbuscular mycorrhizal fungus) (Glomus intraradices)
9.B.198.1.5









Uncharacterized protein of 1234 aas and 1 or more TMSs

Eukaryota
Fungi
UP of Mucor circinelloides (Mucormycosis agent) (Calyptromyces circinelloides)
9.B.198.2.1









LAM2 (YSP2) of 1438 aas and 1 or more TMSs

Eukaryota
Fungi
LAM2 of Saccharomyces cerevisiae
9.B.198.2.2









LAM4 (LTC3) OF 1345 aas and 1 or more TMSs.

Eukaryota
Fungi
LAM4 of Saccharomyces cerevisiae
9.B.198.2.3









LAM5 (LTC2) of 674 aas and 1 or more TMSs

Eukaryota
Fungi
LAM5 of Saccharomyces cerevisiae
9.B.198.2.4









Membrane-anchored lipid-binding protein, LAM6 or LTC1, of 693 aas and 1 (or more) TMSs (Wong and Levine 2016). It is involved in regulating various organellar membrane contact sites (Elbaz-Alon et al. 2015) and is involved in sterol transfer between intracellular membranes (Gatta et al. 2015). It selectively transports sterols between membranes in vivo and in vitro, and is involved in stress-dependent formation of sterol-enriched vacuolar membrane domains (Murley et al. 2015).

Eukaryota
Fungi
LAM6 of Saccharomyces cerevisiae
9.B.198.2.5









GRAM domain-containing protein 1B, GRAMD1B or ASTER-B, of 738 aas and 1 (or possibly more) TMSs. ASTER-A, B and C (TC#s 9.B.198.2.6, 5 and 7) can form homomeric and heteromeric complexes to move cholesterol and possibly phosphatidyl serine from the plasma membrane to the ER membrane (Naito and Saheki 2021).

Eukaryota
Metazoa
GRAM domain protein 1B of Homo sapiens
9.B.198.2.6









GRAMD1A or Aster-A of 724 aas and 1 TMS near the C-terminus of the protein. It is a cholesterol transporter that mediates non-vesicular transport of cholesterol from the plasma membrane (PM) to the endoplasmic reticulum (ER) and  contains unique domains for binding cholesterol and the PM, thereby serving as a molecular bridge for the transfer of cholesterol from the PM to the ER. It plays a crucial role in cholesterol homeostasis and has the unique ability to localize to the PM based on the level of membrane cholesterol. In lipid-poor conditions, it localizes to the ER membrane, and in response to excess cholesterol in the PM is recruited to the endoplasmic reticulum-plasma membrane contact sites (EPCS) which is mediated by the GRAM domain. At the EPCS, the sterol-binding VASt/ASTER domain binds to the cholesterol in the PM and facilitates its transfer from the PM to ER. It may play a role in tumor progression, and plays a role in autophagy regulation while being required for biogenesis of the autophagosome which requires its cholesterol-transfer activity (Laraia et al. 2019).

Eukaryota
Opisthokonta
GRAMD1A of Homo sapiens
9.B.198.2.7









GRAMD1C or Aster-C of 662 aas and 4 C-terminal TMSs. In lipid-poor conditions, it localizes to the ER membrane and in response to excess cholesterol in the plasma membrane (PM), it is recruited to the endoplasmic reticulum-plasma membrane contact sites (EPCS) which is mediated by the GRAM domain. At the EPCS, the sterol-binding VASt/ASTER domain binds to cholesterol in the PM and facilitates its transfer from the PM to ER.The GRAMDs form homo- and hetero-meric complexes to sense the levels of cholesterol in the PM and regulate transport of accessible PM cholesterol to the ER in order to maintain cholesterol homeostasis (Naito and Saheki 2021).

 

Eukaryota
Opisthokonta
GRAMD1C of Homo sapiens