RhoA and Rac1 have been implicated in the mechanism of CCK-induced amylase secretion from pancreatic acini. In all cell types studied to date, inactive Rho GTPases are present in the cytosol bound to the guanine nucleotide dissociation inhibitor RhoGDI. Here, we identified the switch mechanism regulating RhoGDI1-Rho GTPase dissociation and RhoA translocation upon CCK stimulation in pancreatic acini. We found that both Gα13 and PKC, independently, regulate CCK-induced RhoA translocation and that the PKC isoform involved is PKCα. Both RhoGDI1 and RhoGDI3, but not RhoGDI2, are expressed in pancreatic acini. Cytosolic RhoA and Rac1 are associated with RhoGDI1, and CCK-stimulated PKCα activation releases the complex. Overexpression of RhoGDI1, by binding RhoA, inhibits its activation, and thereby, CCK-induced apical amylase secretion. RhoA translocation is also inhibited by RhoGDI1. Inactive Rac1 influences CCK-induced RhoA activation by preventing RhoGDI1 from binding RhoA. By mutational analysis we found that CCK-induced PKCα phosphorylation on RhoGDI1 at Ser96 releases RhoA and Rac1 from RhoGDI1 to facilitate Rho GTPases signaling.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3679036 | PMC |
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0066029 | PLOS |
Theriogenology
December 2024
College of Animal Science and Technology, Jilin Agricultural University, Changchun, 130118, China; Key Laboratory for Animal Production, Product Quality and Safety of Ministry of Education, Changchun, 130118, China. Electronic address:
Wanxi white goose is an important male parent in crossbreeding of Chinese geese, but its short reproductive cycle restricts its application in Northeast China. Therefore, understanding the potential mechanism of breeding period regulation in Wanxi white goose will help to provide more options for crossbreeding. In this study, the reproductive period was divided into prophase (T1), metaphase (T2) and anaphase (T3) according to the laying rhythm of geese.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15260, United States.
Small GTPases (smG) are a 150-member family of proteins, comprising five subfamilies: Ras, Rho, Arf, Rab, and Ran-GTPases. These proteins function as molecular switches, toggling between two distinct nucleotide-bound states. Using traditional multidimensional heteronuclear NMR, even for single smGs, numerous experiments, high protein concentrations, expensive isotope labeling, and long analysis times are necessary.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
December 2024
Shenzhen Key Laboratory of Metabolism and Cardiovascular Homeostasis, Shenzhen University Medical School, Shenzhen University, Shenzhen, Guangdong 518055, China.
Increasing evidence suggests that tumor cells exhibit extreme plasticity in migration modes in order to adapt to microenvironments. However, the underlying mechanism for governing the migration mode switching is still unclear. Here, we revealed that epithelial tumor cells could develop a stable directional mode driven by hyperactivated ERK activity.
View Article and Find Full Text PDFDrug Dev Ind Pharm
November 2024
Microbiome System Engineering Research Center, Prince of Songkla University, Songkhla, Thailand.
bioRxiv
October 2024
Departments of Ophthalmology, Pathology and Cell Biology, Columbia University, New York, NY 10032, USA.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!