The GTPase RAB6 is required for stem cell maintenance and cell migration in the gut epithelium.

Intestinal epithelial cells, which are instrumental in nutrient absorption, fluid regulation, and pathogen defense, undergo continuous proliferation and differentiation within the intestinal crypts, migrating towards the luminal surface where they are eventually shed. RAB GTPases are key regulators of intracellular vesicular trafficking and are involved in various cellular processes, including cell migration and polarity. Here, we investigated the role of RAB6 in the development and maintenance of the gut epithelium.

BIN1 regulates actin-membrane interactions during IRSp53-dependent filopodia formation.

Amphiphysin 2 (BIN1) is a membrane and actin remodeling protein mutated in congenital and adult centronuclear myopathies. Here, we report an unexpected function of this N-BAR domain protein BIN1 in filopodia formation. We demonstrated that BIN1 expression is necessary and sufficient to induce filopodia formation.

Transforming growth factor-beta1 modulates angiotensin II-induced calcium release in vascular smooth muscle cells from spontaneously hypertensive rats.

Objectives: To investigate the role of transforming growth factor-beta1 (TGF-beta1) on Ca2+-dependent mechanisms elicited by angiotensin II in aortic vascular smooth muscle cells (VSMC) of Wistar- Kyoto (WKY) rats and spontaneously hypertensive rats (SHR).

Methods: Cai2+ release induced by angiotensin II (1 micromol/ l) was studied in cultured VSMC isolated from the aortas of 6-week-old WKY rats and SHR. Intracellular Ca2+ (Cai2+) was assessed in Fura-2 loaded cells using fluorescent imaging microscopy.

Extracellular signal-regulated kinase pathway is involved in basic fibroblast growth factor effect on angiotensin II-induced Ca(2+) transient in vascular smooth muscle cell from Wistar-Kyoto and spontaneously hypertensive rats.

We studied the effect of basic fibroblast growth factor (b-FGF) on different Ca(2+) mechanisms elicited by angiotensin II (Ang II) in normotensive Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR). Intracellular Ca(2+) (Ca(2+)(i)) variations were studied in cultured vascular smooth muscle cells (VSMCs) isolated from the aorta of 5- to 6-week-old WKY rats and SHR. Ca(2+)(i) was assessed in Fura-2-loaded cells with fluorescent imaging microscopy.

Several interesting phenotypes of the AT1 receptor produced by site-directed mutagenesis.

The angiotensin II (AngII) AT1 receptor is a seven-transmembrane domain receptor coupled to a Gq/11 protein and phospholipase C, but also to other G proteins and to several tyrosine kinase pathways. These signaling pathways transduce inside the cells the classical actions of AngII (vasoconstriction, aldosterone secretion, etc.), but also the mitogenic action of this vasoactive peptide.