OSBPL5
Description
The OSBPL5 (oxysterol binding protein like 5) is a protein-coding gene located on chromosome 11.
OSBPL5 is a human gene encoding a member of the oxysterol-binding protein (OSBP) family, which are intracellular lipid receptors. Most OSBP family members have an N-terminal pleckstrin homology domain and a highly conserved C-terminal OSBP-like sterol-binding domain. Several transcript variants encoding different isoforms have been identified.
OSBPL5 acts as a lipid transporter mediating countertransport between the endoplasmic reticulum (ER) and the plasma membrane. It specifically exchanges phosphatidylserine (PS) for phosphatidylinositol 4-phosphate (PI4P), delivering PS to the plasma membrane while retrieving PI4P, which is then degraded by the SAC1/SACM1L phosphatase in the ER. OSBPL5 binds PS and PI4P in a mutually exclusive manner. It is suggested that OSBPL5 may cooperate with NPC1 in facilitating cholesterol exit from endosomes/lysosomes. Furthermore, OSBPL5 is known to bind 25-hydroxycholesterol and cholesterol.
OSBPL5 is also known as OBPH1, ORP5.
