Disease relevance of Rap1b

• These findings indicate that hyperglycemia and HG cause an activation and up-regulation of Rap1b in renal glomeruli and in cultured MCs, which then stimulates FN synthesis [1].

High impact information on Rap1b

• Here we report that cAMP-dependent hormonal stimulation of DNA synthesis requires Rap1b in a manner dependent on its phosphorylation by protein kinase A [2].
• The oncogenic property of Rap1b was revealed in a model system in which cAMP stimulates cell proliferation and was linked to Rap's ability to promote S phase entry [2].
• We have now tested the significance of the mitogenic action of Rap1b in a physiologically relevant model, the differentiated thyroid follicular cells, a system that requires thyroid-stimulating hormone (TSH), acting via cAMP, to mediate a full mitogenic response [2].
• Similarly, in vitro exposure of MCs to HG led to an up-regulation of Rap1b with concomitant increase in fibronectin (FN) mRNA and protein expression [1].
• Transfection of Rap1b mutants S17N (Ser --> Asn) or T61R (Thr --> Arg) in MCs inhibited the HG-induced increased FN synthesis [1].

Biological context of Rap1b

• Rap1b can be activated by cAMP, an intracellular message known to either stimulate or inhibit cell proliferation [2].

Associations of Rap1b with chemical compounds

• High glucose stimulates synthesis of fibronectin via a novel protein kinase C, Rap1b, and B-Raf signaling pathway [1].

Other interactions of Rap1b

• B-Raf, and not Raf-1, expression was increased in MCs transfected with Rap1b [1].

References