Stephen Royle

We were asked to write a
[Preview](http://dx.doi.org/10.1016/j.devcel.2015.04.007) piece for
Developmental Cell. Two interesting papers which deal with the insertion
of amphipathic helices in membranes to influence membrane curvature
during endocytosis were scheduled for publication and the journal wanted
some "front matter" to promote them.

Our Preview is paywalled -- sorry about that -- but I can briefly tell
you why these two papers are worth a read.

The [first paper](http://dx.doi.org/10.1016/j.devcel.2015.02.023) -- a
collaboration between EMBL scientists led by Marko Kaksonen -- deals
with the yeast proteins Ent1 and Sla2. Ent1 has an ENTH domain and Sla2
has an ANTH domain. ENTH stands for Epsin N-terminal homology
whereas ANTH means AP180 N-terminal homology. These two domains are
known to bind membrane and in the case of ENTH to tubulate and
vesiculate giant unilamellar vesicles (GUVs). Ent1 does this via an
amphipathic helix "Helix 0" that inserts into the outer leaflet to bend
the membrane. The new paper shows that Ent1 and Sla2 can bind together
(regulated by PIP2) and that ANTH regulates ENTH so that it doesn't make
lots of vesicles, instead the two team up to make regular membrane
tubules. The tubules are decorated with a regular "coat" of these
adaptor proteins. This coat could prepattern the clathrin lattice. Also,
because Sla2 links to actin, then actin can presumably pull on this
lattice to help drive the formation of a new vesicle. The regular
spacing might distribute the forces evenly over large expanses of
membrane.

The [second paper](http://dx.doi.org/10.1016/j.devcel.2015.03.002) --
from David Owen's lab at CIMR in Cambridge -- shows that CALM (a protein
with an ANTH domain) actually has a secret Helix 0! They show that this
forms on contact with lipid. CALM influences the size of clathrin-coated
pits and vesicles, by influencing curvature. They propose a model where
cargo size needs to be matched to vesicle size, simply due to the
energetics of pit formation. The idea is that cells do this by
regulating the ratio of AP2 to CALM.

You can read our
[preview](http://dx.doi.org/10.1016/j.devcel.2015.04.007) and the papers
by [Skruzny et al](http://dx.doi.org/10.1016/j.devcel.2015.02.023) and
[Miller et al](http://dx.doi.org/10.1016/j.devcel.2015.03.002) in the
latest issue of Dev Cell.

---

The post title and the title of our Preview is taken from "Zero
Tolerance" by Death from their Symbolic LP. I didn't want to be outdone
by [these Swedish
scientists](http://www.theguardian.com/music/2014/sep/29/swedish-cientists-bet-bob-dylan-lyrics-research-papers)
who have been using Bob Dylan song titles and lyrics in their papers for
years.


We were asked to write a Preview piece for Developmental Cell. Two interesting papers which deal with the insertion of amphipathic helices in membranes to influence membrane curvature during endocytosis were scheduled for publication and the journal wanted some “front matter” to promote them. Our Preview is paywalled – sorry about that – but I can briefly tell you why these two papers are worth a read.

Messaggi di Rogue Scholar

Zero Tolerance