通过活性单体和/卡尔莫杜林对INF2形式的调节
Miriam Lee1, Aiman Jalmukhambetova1, T Emme Burgin2
1Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA.
The Journal of cell biology
|January 7, 2026
概括
甲INF2的活性蛋白聚合是由结合的卡尔莫杜林 (CALM) 和活性蛋白单体结合蛋白调节的,而不是CAP蛋白. 这说明了INF2的清晰度.
科学领域:
- 细胞生物学 细胞生物学
- 生物化学 生物化学
- 分子生物学分子生物学
背景情况:
- 在细胞内增加时,INF2形式素迅速聚合细胞活性,表明复杂调节.
- 在INF2调节过程中,INF2的N端透视抑制域 (DID) 和C端透视自调域 (DAD) 之间存在自身抑制的相互作用.
- DID的突变与人类疾病有关,并导致构成性INF2激活,而DAD与活性单体结合会破坏调节.
研究的目的:
- 通过一种新的无细胞检测方法,研究INF2形式的调节机制.
- 为了阐明结合的calmodulin (CALM) 和actin单体结合蛋白在INF2调节中的作用.
- 重新评估CAP蛋白在INF2抑制中的必要性.
主要方法:
- 开发和利用一种新的无细胞检测方法来详细研究INF2调控.
- 分析INF2与结结卡尔莫杜林 (CALM) 的相互作用.
- 在INF2调节中评估动因单体结合蛋白 (profilin,thymosin) 的作用.
主要成果:
- 与之前的发现相反,INF2规则不需要CAP蛋白质.
- 单体结合蛋白 (如普罗菲林或蒂莫) 的"缓冲"动素对于INF2抑制至关重要.
- 与结合的卡尔莫杜林 (CALM) 通过与其N端结合来激活INF2,这也起到其他调节作用.
结论:
- 动氨酸单体结合蛋白在一般的动氨酸动态之外,在特定调节诸如INF2之类的动氨酸聚合因子方面发挥着至关重要的作用.
- 结合的卡尔莫杜林 (CALM) 是INF2的关键激活剂,与其N端区域相互作用.
- INF2的N端对其调节至关重要,它调解了CALM结合和其他调节功能.
相关概念视频
Generation of Straight or Branched Actin Filaments
3.7K
The straight or branched structure formation of actin filaments is controlled by nucleating proteins such as the formins and Arp2/3 complex. Formin-mediated assembly results in straight filaments, whereas Arp2/3 protein complex-mediated assembly results in branched actin filaments.
Arp2/3 Complex
Arp2/3 complex is a seven-subunit complex consisting of two proteins similar to actin- Arp2 and Arp3, and five other subunits that help keep Arp2 and Arp3 inactive. When required, the complex is...
Arp2/3 Complex
Arp2/3 complex is a seven-subunit complex consisting of two proteins similar to actin- Arp2 and Arp3, and five other subunits that help keep Arp2 and Arp3 inactive. When required, the complex is...
3.7K
Calmodulin-dependent Signaling
6.0K
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,...
6.0K
Actin Polymerization
8.3K
Actin polymerization occurs through the head-to-tail association of binding sites on monomeric actin or G-actin to form filamentous or F-actin. The polymerization can be divided into three phases ̶ nucleation, elongation, and steady-state phase.
The nucleation phase involves forming a stable nucleus consisting of three actin monomers to form a new actin filament. Actin-binding proteins such as formins and Arp2/3 complex help filament growth post-nucleation. The Formins form straight...
The nucleation phase involves forming a stable nucleus consisting of three actin monomers to form a new actin filament. Actin-binding proteins such as formins and Arp2/3 complex help filament growth post-nucleation. The Formins form straight...
8.3K
Mechanism of Filopodia Formation
3.0K
Filopodia are thin, actin-rich cellular protrusions that play an important role in many fundamental cellular functions. They vary in their occurrence, length, and positioning in different cell types, suggesting their diverse roles.
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
3.0K
Actin Filament Depolymerization
3.8K
Actin filaments (F-actin) are composed of actin subunits. The dissociation of actin monomers can occur from either end of F-actin. The rate of dissociation is faster from the minus-end or the pointed end, where the actin subunits exist with a bound ADP, together known as ADP-actin. The depolymerization of F-actin is aided by proteins, including the actin-depolymerizing factor (ADF) and cofilin family of proteins, gelsolin, and glia maturation factor (GMF).
In F-actin, the ADF/cofilin proteins...
In F-actin, the ADF/cofilin proteins...
3.8K
Formation of Higher-order Actin Filaments
3.5K
The polymerization of G-actin monomers into filamentous F-actin is a multi-step process. Once the F-actins are formed, they can bundle together in different arrangements to form higher-order networks and regulate cellular functions. Common examples include the formation of lamellipodia and filopodia at the cell's leading edge by actin reorganization in a migrating cell. The microvilli on the brush border epithelial cells are also formed through the F-actin network.
The high-order actin...
The high-order actin...
3.5K


