Stimulation of a Gs-like G protein in the osteoclast inhibits bone resorption but enhances tartrate-resistant acid phosphatase secretion. by Moonga, B, Pazianas, M, Alam, A, Shankar, V, Huang, C, Zaidi, M

“…Cholera toxin, a Gs stimulator and a selective Q effect agonist, similarly abolished bone resorption and enhanced TRAP secretion. In contrast, pertussis toxin, a Gi inhibitor and a selective R effect agonist, inhibited bone resorption significantly, but slightly reduced enzyme release. …”

Chapter 28 Genetics and cell biology of calcitonin action by Zaidi, M, Moonga, B, Pazianas, M, Shankar, V, Huang, C

“…The R effect is triggered by a rise of cytosolic [Ca2+] and probably involves the activation of a pertussis toxin-sensitive Gq-like G protein. The parallel activation pathways appear to be coupled proximally to separate calcitonin receptor subtypes. …”

Further studies on the mode of action of calcitonin on isolated rat osteoclasts: pharmacological evidence for a second site mediating intracellular Ca2+ mobilization and cell retra... by Alam, A, Bax, C, Shankar, V, Bax, B, Bevis, P, Huang, C, Moonga, B, Pazianas, M, Zaidi, M

“…A novel R effect site, possibly coupled via a pertussis toxin-sensitive G protein to a [Ca2+]i elevating mechanism is predicted from this study.…”