AP-1 complex subunit sigma-2 is a
protein that in humans is encoded by the ''AP1S2''
gene.
Function
Adaptor protein complex 1 is found at the
cytoplasmic
In cell biology, the cytoplasm is all of the material within a eukaryotic cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. Th ...
face of coated
vesicles
Vesicle may refer to:
; In cellular biology or chemistry
* Vesicle (biology and chemistry), a supramolecular assembly of lipid molecules, like a cell membrane
* Synaptic vesicle
; In human embryology
* Vesicle (embryology), bulge-like features o ...
located at the
Golgi complex
The Golgi apparatus (), also known as the Golgi complex, Golgi body, or simply the Golgi, is an organelle found in most eukaryotic cells. Part of the endomembrane system in the cytoplasm, it packages proteins into membrane-bound vesicles insi ...
, where it mediates both the recruitment of
clathrin to the
membrane and the recognition of sorting signals within the cytosolic tails of
transmembrane receptors
Cell surface receptors (membrane receptors, transmembrane receptors) are receptors that are embedded in the plasma membrane of cells. They act in cell signaling by receiving (binding to) extracellular molecules. They are specialized integral m ...
. This complex is a
heterotetramer
A tetrameric protein is a protein with a quaternary structure of four subunits (tetrameric). Homotetramers have four identical subunits (such as glutathione S-transferase), and heterotetramers are complexes of different subunits. A tetramer ca ...
composed of two large, one medium, and one small
adaptin
Clathrin adaptor proteins, also known as adaptins, are vesicular transport adaptor proteins associated with clathrin. These proteins are synthesized in the ribosomes, processed in the endoplasmic reticulum and transported from the Golgi apparatus t ...
subunit. The protein encoded by this gene serves as the small subunit of this complex and is a member of the adaptin protein family.
Transcript variants utilizing alternative
polyadenylation
Polyadenylation is the addition of a poly(A) tail to an RNA transcript, typically a messenger RNA (mRNA). The poly(A) tail consists of multiple adenosine monophosphates; in other words, it is a stretch of RNA that has only adenine bases. In euk ...
signals exist for this gene.
Pathology
Mutations of the AP1S2 gene cause the
Pettigrew syndrome,
which is characterized by
mental retardation and additional highly variable features, including
choreoathetosis,
hydrocephalus,
Dandy–Walker malformation, seizures, and iron or calcium deposition in the brain.
References
External links
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