Hematopoietic progenitor cells (HPCs) are central to hematopoiesis as they provide large numbers of lineage-defined blood cells necessary to sustain blood homeostasis. They are one of the most actively cycling somatic cells, and their precise control is critical for hematopoietic homeostasis. The small GTPase RhoA is an intracellular molecular switch that integrates cytokine, chemokine, and adh...

Translationally controlled tumor protein (TCTP), a repressor for Na,K-ATPase has been implicated in the development of systemic hypertension, as proved by TCTP-over-expressing transgenic (TCTP-TG) mice. Aorta of TCTP-TG exhibited hypercontractile response compared to that of non-transgenic mice (NTG) suggesting dys-regulation of signaling pathways involved in the vascular contractility by TCTP....

Gong, Ming Cui, Isabelle Gorenne, Paul Read, Taiping Jia, Robert K. Nakamoto, Avril V. Somlyo, and Andrew P. Somlyo. Regulation by GDI of RhoA/Rho-kinase-induced Ca21 sensitization of smooth muscle myosin II. Am J Physiol Cell Physiol 281: C257–C269, 2001.—We characterized the role of guanine nucleotide dissociation inhibitor (GDI) in RhoA/Rho-kinase-mediated Ca21 sensitization of smooth muscle...

RhoA plays a multifaceted role in platelet biology. During platelet development, RhoA has been proposed to regulate endomitosis, proplatelet formation, and platelet release, in addition to having a role in platelet activation. These processes were previously studied using pharmacological inhibitors in vitro, which have potential drawbacks, such as non-specific inhibition or incomplete disruptio...

27 Spontaneously hypertensive rats (SHR) are characterized by impaired erectile function and by 28 overactivity of the pro-contractile RhoA/Rho-kinase (RhoA/ROCK) pathway, as compared to their 29 normotensive counterpart, Wistar Kyoto rats. By measuring intracavernous pressure/mean arterial 30 pressure (ICP/MAP) ratio after electrostimulation of the cavernous nerve, we confirmed these findings ...

Type I cGMP-dependent protein kinase (PKG I) plays a major role in vascular homeostasis by mediating smooth muscle relaxation in response to nitric oxide, but little is known about the regulation of PKG I expression in smooth muscle cells. We found opposing effects of RhoA and Rac1 on cellular PKG I expression: (i) cell density-dependent changes in PKG I expression varied directly with Rac1 act...

RhoA, RhoB and RhoC GTPases are over 85% identical at the amino acid level, with RhoA and RhoC differing at only one residue (43) across the initial two-thirds of their sequences. A putative regulatory distinction between the molecules is their capacity to be uniquely activated by guanine nucleotide exchange factors (GEFs). We hypothesize that variation of amino acid residue 43 between RhoA/B (...

Endothelial proliferation, which is an important process in vascular homeostasis, can be regulated by the extracellular microenvironment. In this study we demonstrated that proliferation of endothelial cells (ECs) was enhanced on hydrogels with high stiffness (HSG, 21.5 kPa) in comparison to those with low stiffness (LSG, 1.72 kPa). ECs on HSG showed markedly prominent stress fibers and a highe...

Diabetic retinopathy (DR) is a well-known serious complication of diabetes mellitus (DM), and can eventually advance to end-stage blindness. In the early stage of DR, endothelial cell barrier disorganized primarily and tight junction (TJ) protein composition transformed subsequently. The small GTPase RhoA and its downstream effector Rho-associated coiled-coil containing protein kinase 1 (ROCK1)...

e already knew the players—MgcRacGAP, Aurora B, and RhoA—and that knocking out any one of them caused failure of cytokinesis; but it wasn’t clear how they were connected. Now, it appears that Aurora B phosphorylates the GAP domain of MgcRacGAP, allowing it to turn its GAP activity toward RhoA, according to data from Yukinori Minoshima, Toshiyuki Kawashima, Toshio Kitamura (University of Tokyo, ...