Endoglin

Endoglin (ENG) is a type I membrane glycoprotein located on cell surfaces and is part of the TGF beta receptor complex. It is also commonly referred to as CD105, END, FLJ41744, HHT1, ORW and ORW1. It has a crucial role in angiogenesis, therefore, making it an important protein for tumor growth, survival and metastasis of cancer cells to other locations in the body.

Gene and expression

The human endoglin gene is located on human chromosome 9 with location of the cytogenic band at 9q34.11. Endoglin glycoprotein is encoded by 39,757 bp and translates into 658 amino acids.

The expression of the endoglin gene is usually low in resting endothelial cells. This, however, changes once neoangiogenesis begins and endothelial cells become active in places like tumor vessels, inflamed tissues, skin with psoriasis, vascular injury and during embryogenesis. The expression of the vascular system begins at about 4 weeks and continues after that. Other cells in which endoglin is expressed consist of monocytes, especially those transitioning into macrophages, low expression in normal smooth muscle cells, high expression vascular smooth muscle cells and in kidney and liver tissues undergoing fibrosis.

Loading... please wait...

This page contains text from Wikipedia, the Free Encyclopedia - https://wn.com/Endoglin

Loop (knot)

In reference to knots, loop may refer to:

One of the fundamental structures used to tie knots. Specifically, it is a U-form narrower than a bight.

A type of knot used to create a closed circle in a line.

References

↑ Clifford W. Ashley, The Ashley Book of Knots. Image 31, 32.

Turn (biochemistry)

A turn is an element of secondary structure in proteins where the polypeptide chain reverses its overall direction. For beta turns go to Beta turn.

Definition

According to one definition, a turn is a structural motif where the C^α atoms of two residues separated by few (usually 1 to 5) peptide bonds are close (< 7 Å), while the residues do not form a secondary structure element such as an alpha helix or beta sheet with regularly repeating backbone dihedral angles. Although the proximity of the terminal C^α atoms usually correlates with formation of a hydrogen bond between the corresponding residues, a hydrogen bond is not a requirement in this turn definition. That said, in many cases the H-bonding and C^α-distance definitions are equivalent.

Types of turns

Turns are classified according to the separation between the two end residues:

In an α-turn the end residues are separated by four peptide bonds (

i \rightarrow i\pm 4

).

In a β-turn (the most common form), by three bonds (

i \rightarrow i\pm 3

).

In a γ-turn, by two bonds (

i \rightarrow i\pm 2

).

Loopback

Loopback, or loop-back, refers to the routing of electronic signals, digital data streams, or flows of items back to their source without intentional processing or modification. This is primarily a means of testing the transmission or transportation infrastructure.

Many example applications exist. It may be a communication channel with only one communication endpoint. Any message transmitted by such a channel is immediately and only received by that same channel. In telecommunications, loopback devices perform transmission tests of access lines from the serving switching center, which usually does not require the assistance of personnel at the served terminal. Loop around is a method of testing between stations that are not necessarily adjacent, where in two lines are used, with the test being done at one station and the two lines are interconnected at the distant station. A patch cable may also function as loopback, when applied manually or automatically, remotely or locally, facilitating a loop-back test.