CDC42 drives RHOA activity and actin polymerization during capacitation

Abstract

<jats:p>Mammalian sperm cells acquire fertilizing capacity as a result of a process termed capacitation. Actin polymerization is important for capacitation; inhibiting actin polymerization prevents the adhesion and fusion of the sperm with the ovule. The main function of Rho proteins Cdc42 and RhoA is to direct actin polymerization. Although these two Rho proteins are present in mammalian sperm, little is known about their role in capacitation, the acrosome reaction, and the way in which they direct actin polymerization. The purpose of this study was to determine the participation of Cdc42 and RhoA in capacitation and the acrosome reaction and their relationship with actin polymerization using guinea pig sperm. Our results show that the inhibition of Cdc42 and RhoA alters the kinetics of actin polymerization, capacitation, and the acrosome reaction in different ways. Our results also show that the initiation of actin polymerization and RhoA activation depend on the activation of Cdc42 and that RhoA starts its activity and effect on actin polymerization when Cdc42 reaches its maximum activity. Given that the inhibition of ROCK1 failed to prevent the acrosomal reaction, the participation of RhoA in capacitation and the acrosomal reaction is independent of its kinase 1 (ROCK1). In general, our results indicate that Cdc42 and RhoA have different roles in capacitation and acrosomal reaction processes and that Cdc42 plays a preeminent role.</jats:p>

The relationship of blood CDC42 level with Th1 cells, Th17 cells, inflammation markers, disease risk/activity, and treatment efficacy of rheumatoid arthritis

“…Cell division control protein 42 (CDC42), a type of small GTPase belonging to the Rho family, has been reported to be involved in regulating actin polymerization and epithelial polarity [9,10]. In addition, CDC42 also participates in modulating immune response by interacting with neutrophils, T cells, and B cells to maintain their identity, promote cell differentiation, and activate their function [11][12][13][14].…”

Nano−/micro‐scaled hydroxyapatite ceramic construction and the regulation of immune‐associated osteogenic differentiation

“…Cdc42 is an important factor that regulates cells' actin cytoskeleton arrangement, even to induce the formation of cell filopodia, and the actin remodeling will influence its migration further as well as the subcellular localization. [42][43][44] It suggested a fact that the difference in surface topography between m-HA and n-HA makes a significant impact on immune activities. And the regulation of biomaterial surface properties on MSCs osteogenic differentiation was largely determined by the immune activities and related signal transduction.…”

Signaling Proteins Recruited to the Sperm Binding Site: Role of β-Catenin and Rho A

“…The distribution of Rho A (green) at the sperm binding site (n = 24 oocytes) was complicated by the fact that the sperm acrosomal region contains significant Rho A (Ducummon and Berger, 2006;Reyes-Miguel et al, 2020). However, depending on the angle of the image plane, Rho A concentrated in the underlying oocyte cortex could be distinguished from the Rho A bound to sperm (Figures 2A,B).…”