X-Nico

2 unusual facts about endoplasmic reticulum


Endoplasmic reticulum

The lacey membranes of the endoplasmic reticulum were first seen in 1945 by Keith R. Porter, Albert Claude, Brody Meskers and Ernest F. Fullam.

Ocular albinism type 1

These melanin macroglobules are probably formed due to failure of melanosomes to separate from the ER-golgi system with the accumulation of enzymes and other secretory proteins leading to an increase organelle size.


ALG13

It heterodimerizes with asparagine-linked glycosylation 14 (ALG14) homolog to form a functional UDP-GlcNAc glycosyltransferase that catalyzes the second sugar addition of the highly conserved oligosaccharide precursor in endoplasmic reticulum N-linked glycosylation.

O-linked glycosylation

Both of these fucosyltransferases have been localized to the endoplasmic reticulum, which is unusual for glycosyltransferases, most of which function in the Golgi apparatus.

Secretory protein

This sequence is recognised by a cytosolic protein, SRP (Signal Recognition Particle), which stops the translation and aids in the transport of the mRNA-ribosome complex to an SRP receptor found in the membrane of the endoplasmic reticulum.


see also

Aminopeptidase

CDNA sequences are available for several aminopeptidases and a crystal structure of the open state of human endoplasmic reticulum Aminopeptidase 1 ERAP1 is presented here.

Kifunensine

In the lysosomal storage disorders Gaucher’s and Tay-Sachs disease, endoplasmic reticulum-associated degradation (ERAD) prevents the native folding of mutated lysosomal enzymes in a patient’s fibroblasts.

P180

RRBP1 (also known as p180), a human gene that encodes a membrane-bound protein of the endoplasmic reticulum.

Translocon

ER-proteins are degraded in the cytosol by the 26S proteasome, a process known as Endoplasmic-reticulum-associated protein degradation, and therefore have to be transported by an appropriate channel.