Talk:Arp2/3 complex

Out of Date Information

The information in this article is now out of date. New evidence has arisen that the 70 degree branching by the Arp2/3 complex is an artefact from critical-point drying for electron microscopy. This article should be updated with the new findings. Please see "Unravelling the structure of the lamellipodium" by Small, et al 2008, Journal of Microscopy 231(3):479 Marv101 (talk) 22:33, 19 February 2010 (UTC)

The above statement is not correct. Evidence from many laboratories has established that the Arp2/3 complex nucleates new filaments from the sides of pre-existing filaments. These experiments include electron microscopy of various fixed samples as well as bulk biochemical studies and real-time observations of filament branching by TIRF microscopy. The controversy created by Small et al. 2008 regards the degree to which this branching persists at the leading edge of migrating cells and it is fair to say that large majority of the field is skeptical of the extreme position represented by Small et al. 2008 (Higgs HN. 2011 Trends Cell Biol. 21(1):2-4; Insall RH. 2011 Trends Cell Biol. 21(1):2). —Preceding unsigned comment added by Actinman (talk • contribs) 04:49, 20 May 2011 (UTC)

In further response to the first comment above, it now appears that the results of Small et al. (2008) suffer from significant data processing artefacts and/or observer bias. For details, see Yang and Svitkina (2011, Nature Cell Biology 13, 1012–1013). — Preceding unsigned comment added by 169.230.6.120 (talk) 00:13, 3 September 2011 (UTC)

older entries

Hey, I am not sure if the article is that good yet. I am planning to keep improving it though. --Splette 15:14, 27 February 2006 (UTC)

I think it should say that in the barbed-branching model arp2/3 associates with the pointed end. I couldn't access the article.

amulekii

• Hi Amulekii, no that appears to be wrong. Just as written in the article in the barbed-branching model arp2/3 associates with the barbed end. Here is a good article from Biochem J, freely accessible: Signalling to actin assembly via the WASP-family proteins and the Arp2/3 complex In the article they summarize the existing models: "Despite the popularity of the dendritic-nucleation model, data obtained by other groups have led to the development of an alternative barbed-end branching model. Pantaloni et al. proposed that activated Arp2/3 complex binds to the barbed end of the actin filament, rather than at the side, and that the rate of Arp2/3-mediated actin polymerization is proportional to the number of free barbed ends, not the total length of the actin mother filament." I hope this clears things up a bit. Thanks for contacting me on my talk page about it. --Splette ^Talk 13:14, 18 May 2006 (UTC)

Oh yeah. I got you. I should have looked more carefully at the pictures you provided. Amulekii 21:37, 18 May 2006 (UTC)

Shouldn't it say Wiskott-Aldrich Syndrome Protein family instead of Wiskott-Aldrich Syndrome family protein? Amulekii 21:43, 18 May 2006 (UTC)

Arp2/3 in plants?

Hi there, in the summary it is said that "[the Arp2/3 complex] is found in most eukaryotic organisms, but absent from a number of Chromalveolates and plants.[2]" This is misleading because plants do have an Arp2/3 complex.

But then in the section "Cellular uses of Arp2/3" one can read: "Moreover, recent studies show that the Arp2/3 complex is essential for proper polar cell expansion in plants. Arp2/3 mutations in Arabidopsis thaliana result in abnormal filament organization, which in turn affects the expansion of trichomes, pavement cells, hypocotyl cells, and root hair cells.[21][22]"

The article from reference [2] says that WASP is not found in plants, but they do have SCAR/WAVE proteins.

Best, N1K0W1N (talk) 04:32, 24 October 2019 (UTC)