The endoplasmic-reticulum–Golgi intermediate compartment (ERGIC) is an

organelle In cell biology, an organelle is a specialized subunit, usually within a cell (biology), cell, that has a specific function. The name ''organelle'' comes from the idea that these structures are parts of cells, as Organ (anatomy), organs are to th ...

in eukaryotic cells. This compartment mediates transport between the

endoplasmic reticulum The endoplasmic reticulum (ER) is a part of a transportation system of the eukaryote, eukaryotic cell, and has many other important functions such as protein folding. The word endoplasmic means "within the cytoplasm", and reticulum is Latin for ...

(ER) and

Golgi complex The Golgi apparatus (), also known as the Golgi complex, Golgi body, or simply the Golgi, is an organelle found in most eukaryotic Cell (biology), cells. Part of the endomembrane system in the cytoplasm, it protein targeting, packages proteins ...

, facilitating the sorting of cargo. The cluster was first identified in 1988 using an antibody to the protein that has since been named

ERGIC-53 Protein ERGIC-53 also known as ER-Golgi intermediate compartment 53 kDa protein or lectin mannose-binding 1 is a protein that in humans is encoded by the ''LMAN1'' gene. Function ERGIC-53 (also named LMAN1) is a type I integral membrane protei ...

. It is also referred to as the vesicular-tubular cluster (VTC) or, originally, tubulo-vesicular compartment. In

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

ian organisms,

COPII The coat protein complex II, or COPII, is a group of proteins that facilitate the formation of vesicles to transport proteins from the endoplasmic reticulum to the Golgi apparatus or endoplasmic-reticulum–Golgi intermediate compartment. Thi ...

vesicles that have budded from exit sites in the endoplasmic reticulum lose their coats and fuse to form the vesicular-tubular cluster (VTC). Retrieval (or retrograde) transport in

COPI COPI is a coatomer, a protein complex that coats vesicle (biology), vesicles transporting proteins from the ''cis'' end of the Golgi complex back to the rough endoplasmic reticulum (ER), where they were originally Translation (genetics), synthesi ...

vesicles returns many of the lost ER resident proteins back to the endoplasmic reticulum. Forward (or anterograde) transport moves the VTC contents to the cis-Golgi network, the receiving face of the Golgi complex. This process is thought to occur by one of two processes. One is known as cisternal maturation where the VTC simply matures into the cis-Golgi network. In another,

vesicular transport moves VTC material to the receiving face of the Golgi apparatus through movement of the VTC along microtubules. Evidence exists for both processes and it may be that both occur simultaneously in cells.

References

{{reflist Organelles