通过其 PDZ 域对 LIM 激酶进行自我调节
Gabriela Casanova-Sepúlveda1, Joel A Sexton2, Benjamin E Turk2
1Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, 06520, USA.
Nature communications
|December 19, 2023
概括
LIMK2的PDZ域具有独特的结构,这表明它具有新的监管作用. 这个域对LIMK1和LIMK2自身调节至关重要,影响着actin细胞骨动力学.
科学领域:
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
- 生物化学 生物化学
背景情况:
- LIM域激酶 (LIMK) 通过酸化cofilin来调节动因细胞骨架的重塑.
- LIMKs是Rho GTPase信号传递和actin动态之间的关键联系.
- 精确的LIMK N-终端区域和PDZ域的功能尚未完全理解.
研究的目的:
- 为了确定LIMK2 PDZ域的晶体结构.
- 为了研究PDZ域在LIMK自我调节中的功能意义.
- 阐明PDZ领域在控制LIMK活动中的作用.
主要方法:
- 使用X射线晶体学来确定LIMK2 PDZ域的2.0 Å结构.
- 用于研究特定表面残留物的功能重要性,采用了位点定向的突变发生.
- 在酵母和体外激酶试验中使用LIMK1的子宫外表达来评估蛋白质活性.
主要成果:
- LIMK2 PDZ域结构揭示了一些不寻常的特征,包括面向核心的氨酸和浅层的结合裂.
- 在PDZ域中确定了一个高度保守的远端表面.
- 在LIMK1中这种表面的突变导致酵母生长减少,表明激酶活性增加,而体外分析证实了PDZ域突变的过酸化和活性升高.
- 发现这种表面对于自调节至关重要,独立于激活循环酸化.
结论:
- LIMK2的PDZ域具有独特的结构,表明它具有非正规的功能.
- 在LIMK PDZ域上的保留表面在LIMK1和LIMK2活动的自我调节中起着至关重要的作用.
- 这些发现突显了PDZ域在控制LIMK介导的动力学中的功能重要性.
相关概念视频
The JAK-STAT Signaling Pathway
8.9K
Several cytokine receptors have tightly bound Janus kinase or JAK proteins attached at their cytosolic tail. Small signaling molecules such as cytokines, growth hormones, or prolactins bind to the cytokine receptors and initiate their dimerization. The dimerization brings the cytosolic JAKs together that trans-phosphorylate and activates each other. The activated JAKs now phosphorylate cytosolic tails of the cytokine receptors, which serve as binding sites for adaptor proteins such as SH2...
8.9K
PI3K/mTOR/AKT Signaling Pathway
3.6K
The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast, mTORC2 consists of a...
3.6K
Amplifying Signals via Enzymatic Cascade
8.5K
When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function or allow its binding to other molecules. The initial signal is amplified by most signal transduction pathways. This means that a single ligand molecule can activate multiple molecules of a downstream target. Proteins that relay a signal are most commonly phosphorylated at one or more sites, activating or inactivating the protein. Kinases catalyze...
8.5K
Receptor Tyrosine Kinases
13.0K
Receptor tyrosine kinases or RTKs are membrane-bound receptors that phosphorylate specific tyrosine on protein substrates. RTKs regulate cellular growth, differentiation, survival, and migration. They contain an extracellular ligand binding domain, a transmembrane domain, and a cytosolic tail with intrinsic kinase activity. Several extracellular signaling molecules activate RTKs in one or more ways and relay the signal downstream. Ligands such as platelet-derived growth factor (PDGF) or...
13.0K
Calmodulin-dependent Signaling
5.1K
Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
5.1K
Regulation of Angiogenesis and Blood Supply
2.6K
Rapidly dividing tumors, embryos, and wounded tissues require more oxygen than usual, lowering the oxygen concentration in the blood. At low oxygen or hypoxic conditions, an oxygen-sensitive transcription factor called the hypoxia-inducible factor 1 or HIF1 is activated. HIF1 is a dimeric protein of alpha (ɑ) and beta (β) subunits. Under optimal oxygen conditions, HIF1β is present in the nucleus while HIF1ɑ remains in the cytosol. HIF1ɑ is hydroxylated by prolyl...
2.6K


