Saccharomyces cerevisiae Seipin and similar proteins
Seipin is a homo-oligomeric integral membrane protein in the endoplasmic reticulum (ER) that concentrates at junctions with cytoplasmic lipid droplets (LDs). It acts as a cell-autonomous regulator of lipolysis essential for adipocyte differentiation. Seipin is predicted to contain two transmembrane domains at N-terminus and C-terminus, respectively. This model corresponds to a group of seipins from Saccharomycotina. Saccharomyces cerevisiae seipin (Sei1), also called few lipid droplets protein 1 (Fld1p), is involved in lipid metabolism and lipid droplet (LD) morphology, number, and size. It facilitates initiation of LD formation and ensures that vectorial budding of LDs from the ER is directed towards the cytoplasm. In contrast to human seipin, Sei1-mediated LD formation depends on Ldb16, a yeast specific binding partner. Sei1 forms a homodecameric ring that scaffolds and positions Ldb16.
Structure:7OXP; Saccharomyces cerevisiae seipin forms a homodecamer, contacts at 4A
Comment:Sei1-mediated LD formation depends on Ldb16, a yeast specific binding partner. Sei1 forms a homodecameric ring that scaffolds and positions Ldb16.
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