In:
eLife, eLife Sciences Publications, Ltd, Vol. 4 ( 2015-11-09)
Abstract:
Most types of cells in humans and other animals have slender, hair-like structures known as cilia that project out of the cell surface. These structures sense and respond to signals from the external environment and are crucial for organisms to develop normally. Defects in cilia can lead to many serious conditions such as Joubert syndrome, which affects the development of the brain and other organs in humans. The Arl family of “G-proteins” play important roles in the formation and operation of cilia. They contain a section called a G-protein domain whose activity can be switched on by interactions with other proteins called guanine nucleotide exchange factors (or GEFs for short). A member of the Arl family called Arl3 is found in higher amounts in cilia than in other parts of the cell. It is involved in the transport of proteins to the cilia from other parts of the cell, but it is not known which GEFs are able to activate it. Here, Gotthardt, Lokaj et al. used several biochemical techniques to show that another member of the Arl family called Arl13B actually acts as a GEF to activate Arl3 in cilia. Arl13B is only found in cilia and the GEF activity relies on its G-protein domain and another element at one end called a C-terminal helix. Previous studies have shown that mutations in the gene that encodes Arl13B can cause Joubert syndrome in humans. Gotthardt, Lokaj et al. found that mutant forms of Arl13B had significantly lower GEF activity than normal Arl13B proteins. Together, Gotthardt, Lokaj et al.’s findings provide an explanation for why Arl3 is only activated in cilia even though it is found throughout the cell. Further work is needed to understand how the activity of Arl13B is regulated.
Type of Medium:
Online Resource
ISSN:
2050-084X
DOI:
10.7554/eLife.11859.001
DOI:
10.7554/eLife.11859.002
DOI:
10.7554/eLife.11859.003
DOI:
10.7554/eLife.11859.004
DOI:
10.7554/eLife.11859.005
DOI:
10.7554/eLife.11859.006
DOI:
10.7554/eLife.11859.007
DOI:
10.7554/eLife.11859.008
DOI:
10.7554/eLife.11859.009
DOI:
10.7554/eLife.11859.010
DOI:
10.7554/eLife.11859.011
DOI:
10.7554/eLife.11859.012
DOI:
10.7554/eLife.11859.013
DOI:
10.7554/eLife.11859.014
DOI:
10.7554/eLife.11859.015
Language:
English
Publisher:
eLife Sciences Publications, Ltd
Publication Date:
2015
detail.hit.zdb_id:
2687154-3