Biochemical analysis of human IQGAP proteins

人类 IQGAP 蛋白的生化分析

• 批准号: BB/D000394/1
• 负责人: David Timson
• 金额: $ 23.08万
• 依托单位: Queen's University Belfast
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2006
• 资助国家: 英国
• 起止时间: 2006 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FD000394%2F1
• 关键词: Biochemical; analysis; human; IQGAP; proteins

In your cells there is a network of proteins called the cytoskeleton. This isn't a very good name because unlike your bones it is constantly being taken apart, put back together and moved around. Its job is to provide support for the cell, to provide tracks for things to move about in the cell on and to help the cell move around. All these activities need to be co-ordinated and if this goes wrong you'll get ill. You might even get cancer. One of the most interesting recent discoveries is that there are a group of proteins whose job it is to help organise the cytoskeleton. These organising proteins (called scaffolding proteins) do more than just bring the right proteins together at the right time. They also talk to other proteins by sticking to them. When two proteins stick to each other messages can be passed between them because of the different shapes the molecules can adopt. So we think these scaffolding proteins listen to what other proteins have to say, work out what it all means and then pass the right message on to the cytoskeleton. You can think of them being like miniature telephone exchanges. We want to know how they work. The particular scaffolding proteins we are interested in are called the IQGAP proteins. In your body you have three different types of IQGAP protein called IQGAP1, IQGAP2 and IQGAP3. Don't worry / the name IQGAP doesn't mean that you're stupid because you have a gap in your IQ. It's actually named after two parts of the protein / the IQ-motifs and the GAP domain. These are two of the bits of the protein which stick to other proteins. The IQ-motifs stick to a protein called calmodulin and the GAP domain to one called CDC42. Both calmodulin and CDC42 are proteins which carry messages round the cell. There's another bit we're interested in called the CHD which sticks to actin. Actin is a protein in the cytoskeleton. So we think IQGAPs collect information from calmodulin and CDC42 and pass it on to actin. We want to find out how they do that. What we're going do is to genetically engineer some bacteria so that they'll make calmodulin and CDC42 for us. IQGAPs are a bit big to do this with and so we'll make fragments of them. Luckily for us, other scientists have already worked out some fragments which bacteria are happy to make. We've also got a problem with actin. Other people have shown that when bacteria make this protein it doesn't work properly. So we'll make that one in yeast instead. Once we've got all these proteins we'll ask how they stick together. We'll try and find out the chemical details of what's going on at the places where the proteins stick together. Of course proteins are very very small and so we can't just look at them. We can't even look at them under a microscope. So we have to use indirect methods using chemistry and physics to find out what's going on. We're also going to find out how tightly they stick / again using chemical and physical methods. Another thing we're very interested in is how IQGAP1, IQGAP2 and IQGAP3 differ from each other. We know that they are quite similar, but we also know that IQGAP1 and IQGAP2 are found in different cells and stick to a slightly different range of other proteins. As for IQGAP3 we really don't know anything about that yet. So anything we discover about it really will be novel. We think that the way each IQGAP sticks to these other proteins will be slightly different and that how strongly they stick will also be different. Hopefully once we know the chemical details about how they stick, we'll also have a good idea about why the strength of stickiness is different. This project is important because the cytoskeleton goes wrong in a lot of diseases and some drugs interact with the cytoskeleton. When we've finished we'll be a bit closer to understanding how these tiny molecular telephone exchanges actually work.

在您的细胞中，有一个称为细胞骨架的蛋白质网络。这不是一个很好的名字，因为与您的骨头不同，它经常被拆开，将其放回在一起并四处走动。它的工作是为单元提供支持，为在单元格上四处移动的事物提供轨道，并帮助单元格移动。所有这些活动都需要协调，如果出错，您会生病。您甚至可能患有癌症。最近发现的最有趣的发现之一是，有一组蛋白质的工作是帮助组织细胞骨架。这些组织蛋白（称为脚手架蛋白）不仅可以在正确的时间将正确的蛋白质融合在一起。他们还坚持与其他蛋白质交谈。当两个蛋白质互相粘在它们之间时，由于分子可以采用的不同形状，它们之间会传递它们。因此，我们认为这些脚手架蛋白质会听取其他蛋白质所说的话，弄清楚这一切的含义，然后将正确的信息传递给细胞骨架。您可以想到它们就像微型电话交换一样。我们想知道它们的工作方式。我们感兴趣的特定脚手架蛋白称为IQGAP蛋白。在您的体内，您有三种不同类型的IQGAP蛋白，称为IQGAP1，IQGAP2和IQGAP3。不用担心 / iQGAP的名字并不意味着您愚蠢，因为您的智商有差距。它实际上是以蛋白质 / IQ-MOTIF和间隙域的两个部分命名的。这是粘在其他蛋白质上的蛋白质的两个部分。 IQ-MOTIFS粘在称为Calmodulin的蛋白质和GAP结构域中，称为CDC42。钙调蛋白和CDC42都是蛋白质，可在细胞周围带有消息。我们感兴趣的另一个名为CHD，它坚持肌动蛋白。肌动蛋白是细胞骨架中的一种蛋白质。因此，我们认为IQGAP从钙调蛋白和CDC42收集信息，并将其传递给肌动蛋白。我们想找出他们如何做到这一点。我们要做的是基因研究一些细菌，以便它们为我们制作钙调蛋白和CDC42。 IQGAP与此操作有点大，因此我们将制作它们的片段。对我们来说幸运的是，其他科学家已经解决了细菌乐于制作的一些碎片。我们也有肌动蛋白有问题。其他人已经表明，当细菌制成这种蛋白质时，它无法正常工作。因此，我们将其改为将其制成酵母。一旦获得所有这些蛋白质，我们将询问它们如何粘在一起。我们将尝试找出蛋白质粘在一起的地方发生的化学细节。当然，蛋白质非常小，所以我们不能只看它们。我们甚至无法在显微镜下看它们。因此，我们必须使用化学和物理学的间接方法来找出正在发生的事情。我们还将找出他们使用化学和物理方法再次粘着 /再次粘着。我们非常感兴趣的另一件事是IQGAP1，IQGAP2和IQGAP3彼此不同。我们知道它们非常相似，但我们也知道IQGAP1和IQGAP2在不同的细胞中发现，并且坚持使用其他蛋白质略有不同的范围。至于IQGAP3，我们真的对此一无所知。因此，我们发现的任何事情确实都是新颖的。我们认为，每个IQGAP坚持这些其他蛋白质的方式都会略有不同，并且它们坚持的粘附方式也会有所不同。希望一旦我们知道它们如何坚持的化学细节，我们也会对为什么粘性的力量不同。该项目很重要，因为细胞骨架在许多疾病中出错，并且某些药物与细胞骨架相互作用。完成后，我们将更加了解这些微小的分子电话交换的实际工作方式。

项目成果

On the Interaction Between Human IQGAP1 and Actin.

• DOI: 10.2174/0929866523666160204123331
• 发表时间: 2016-03
• 期刊: Protein and peptide letters
• 影响因子: 1.6
• 作者: Damian J. Magill;Elaine Hamilton;S. Shirran;C. Botting;D. Timson

IQGAP1 Interaction with RHO Family Proteins Revisited: KINETIC AND EQUILIBRIUM EVIDENCE FOR MULTIPLE DISTINCT BINDING SITES.

• DOI: 10.1074/jbc.m116.752121
• 发表时间: 2016-12-16
• 期刊: The Journal of biological chemistry
• 作者: Nouri K;Fansa EK;Amin E;Dvorsky R;Gremer L;Willbold D;Schmitt L;Timson DJ;Ahmadian MR
• 通讯作者: Ahmadian MR

New model for the interaction of IQGAP1 with CDC42 and RAC1.

• DOI: 10.1080/21541248.2017.1321169
• 发表时间: 2020-01-01
• 期刊: Small GTPases
• 作者: Nouri, Kazem;Timson, David J;Ahmadian, Mohammad R
• 通讯作者: Ahmadian, Mohammad R

LGR5 receptor promotes cell-cell adhesion in stem cells and colon cancer cells via the IQGAP1-Rac1 pathway.

• DOI: 10.1074/jbc.m117.786798
• 发表时间: 2017-09-08
• 期刊: The Journal of biological chemistry
• 作者: Carmon KS;Gong X;Yi J;Wu L;Thomas A;Moore CM;Masuho I;Timson DJ;Martemyanov KA;Liu QJ
• 通讯作者: Liu QJ

IQ-motif selectivity in human IQGAP2 and IQGAP3: binding of calmodulin and myosin essential light chain

• DOI: 10.1042/bsr20100123
• 发表时间: 2011-10-01
• 期刊: BIOSCIENCE REPORTS
• 影响因子: 4
• 作者: Atcheson, Erwan;Hamilton, Elaine;Timson, David J.
• 通讯作者: Timson, David J.