Sucrase-isomaltase (SI) is a glucosidase enzyme located on the brush border of the small intestine. It is a dual-function enzyme with two GH31 domains, one serving as the isomaltase, the other as a sucrose alpha-glucosidase. It has preferential expression in the apical membranes of enterocytes. The enzyme’s purpose is to digest dietary carbohydrates such as starch, sucrose and isomaltose. By further processing the broken-down products, energy in the form of ATP can be generated.
Fatty aldehyde dehydrogenase is an aldehyde dehydrogenase enzyme that in human is encoded in the ALDH3A2 gene on chromosome 17. Aldehyde dehydrogenase enzymes function to remove toxic aldehydes that are generated by the metabolism of alcohol and by lipid peroxidation.
Stromal interaction molecule 1 is a protein that in humans is encoded by the STIM1 gene. STIM1 has a single transmembrane domain, and is localized to the endoplasmic reticulum, and to a lesser extent to the plasma membrane.
Calcium release-activated calcium channel protein 1 is a calcium selective ion channel that in humans is encoded by the ORAI1 gene. Orai channels play an important role in the activation of T-lymphocytes. The loss of function mutation of Orai1 causes severe combined immunodeficiency (SCID) in humans The mammalian orai family has two additional homologs, Orai2 and Orai3. Orai proteins share no homology with any other ion channel family of any other known proteins. They have 4 transmembrane domains and form hexamers.
Membrane-bound transcription factor site-1 protease, or site-1 protease (S1P) for short, also known as subtilisin/kexin-isozyme 1 (SKI-1), is an enzyme that in humans is encoded by the MBTPS1 gene. S1P cleaves the endoplasmic reticulum loop of sterol regulatory element-binding protein (SREBP) transcription factors.
Junctophilin 2, also known as JPH2, is a protein which in humans is encoded by the JPH2 gene. Alternative splicing has been observed at this locus and two variants encoding distinct isoforms are described.
Junctophilin-1 is a protein that in humans is encoded by the JPH1 gene.
Reticulocalbin-2 is a protein that in humans is encoded by the RCN2 gene.
Dolichol phosphate-mannose biosynthesis regulatory protein is a protein that in humans is encoded by the DPM2 gene.
Junctophilin 4 is a protein in humans that is encoded by the JPH4 gene.
Coiled-coil domain containing 109B (CCDC109B) is a potential calcium uniporter protein found in the membrane of human cells and is encoded by the CCDC109B gene. While CCDC109B is a transmembrane protein it is unclear if it is located within the cell membrane or mitochondrial membrane.
Motile sperm domain containing 2 is a protein that in humans is encoded by the MOSPD2 gene. It is an endoplasmic reticulum–resident protein involved in membrane contact site formation.
SRP receptor alpha subunit is a protein that in humans is encoded by the SRPRA gene.
GRAM domain containing 1B, also known as GRAMD1B, Aster-B and KIAA1201, is a protein that is encoded by the GRAMD1B gene. It contains a transmembrane region and two domains of known function; the GRAM domain and a VASt domain. It is predicted to localize in the nucleus, supported by several nuclear transport signals and nuclearly associated motifs. This highly conserved gene is found in a variety of vertebrates and invertebrates, however is not found in bacteria or fungi.
GRAM domain containing 4 (GRAMD4) also known as Death-Inducing Protein (DIP) is a protein that is encoded by the GRAMD4 gene.
GRAM domain containing 1A also known as Aster-A is a protein that is encoded by the GRAMD1A gene. It contains a transmembrane region, a GRAM domain and a VASt domain that can bind cholesterol. GRAMD1A has four paralogs: GRAMD1B and GRAMD1C and two without VASt domains, GRAMD2A and GRAMD2B. These proteins are mammalian representatives of the yeast lipid transfer proteins anchored at a membrane contact site (LAM) family.
3-hydroxyacyl-CoA dehydratase 2 is a protein that in humans is encoded by the HACD2 gene.
GRAM domain containing 1C also known as Aster-C is a protein that is encoded by the GRAMD1C gene. It contains a transmembrane region, a GRAM domain and a VASt domain.
GRAM domain-containing 2B protein, also known as NS3TP2 and HCV NS3-transactivated protein 2 is a protein encoded by the GRAMD2B gene.
VAD1 analog of StAR-related lipid transfer (VASt) is a steroidogenic acute regulatory protein‐related lipid transfer (StART)-like lipid-binding domain first identified in the vad1 protein in Arabidopsis thaliana. Proteins containing these domains are found in eukaryotes and usually contain another lipid-binding domain, typically the GRAM domain and sometimes the C2 domain in plants and the integral peroxisomal membrane peroxin Pex24p domain in oomycetes.
