SAR1 gene homolog B, also known as SAR1B, is a protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 which in humans is encoded by the SAR1B gene

Gene

A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

.

Function

SAR1B belongs to the Sar1-ADP ribosylation factor

ADP ribosylation factor

ADP Ribosylation Factors are members of the ARF family of GTP-binding proteins of the Ras superfamily. ARF family proteins are ubiquitous in eukaryotic cells, and six highly conserved members of the family have been identified in mammalian cells. Although ARFs are soluble, they generally...

 family of small GTPase

GTPase

GTPases are a large family of hydrolase enzymes that can bind and hydrolyze guanosine triphosphate . The GTP binding and hydrolysis takes place in the highly conserved G domain common to all GTPases.-Functions:...

s, which govern the intracellular trafficking

Protein targeting

Protein targeting or protein sorting is the mechanism by which a cell transports proteins to the appropriate positions in the cell or outside of it. Sorting targets can be the inner space of an organelle, any of several interior membranes, the cell's outer membrane, or its exterior via secretion...

 of proteins in coat protein (COP)-coated vesicles.

Clinical significance

Mutations in the SAR1B gene are associated with chylomicron retention disease

Chylomicron retention disease

Chylomicron retention disease is a disorder of fat absorption.It is associated with SAR1B....

(also known as Anderson disease) which is an autosomal recessive disorder of severe fat malabsorption.

Further reading