Rabbit Anti-Human GNA12 (a.a. 301-381) Polyclonal antibody

Microcell hybrid lines of A9 mouse fibrosarcoma containing complete or partially deleted human chromosomes 3 (chr. 3) were inoculated into SCID mice. Cell lines derived from the tumors were examined by fluorescent in situ hybridization for the status of the transferred human chromosome and by PCR for marker loss. The SCID tumors arising after the inoculation of 10(5) cells were passaged serially in vivo and regularly showed loss of four markers; D3S1029 (3p21.3-21.2), AP20R (3p22-21.3, D3S32 (3p21.3-p21.2), and THRB (3p24). This regularly deleted region is bordered by markers GNA12 (3p21.1-p21.3) and VHL (3p25) that were maintained in a fraction of tumors. Fragments derived from the long arm of chromosome 3 and corresponding markers in the 3q26-q28 region were retained in all tumors. Our findings may be related to the postulated presence of tumor suppressor genes in the 3p24-p21 region as indicated by the frequent deletion of this region in renal and small cell lung carcinomas and other solid tumors. The technically cumbersome identification of suppressor genes may be supplemented by an ''elimination test'' based on analogous principles. (C) 1994 Wiley-Liss, Inc.

G protein?coupled receptor signaling is required for the navigation of immune cells along chemoattractant gradients. However, chemoattractant receptors may couple to more than one type of heterotrimeric G protein, each of which consists of a G?, G?, and G? subunit, making it difficult to delineate the critical signaling pathways. Here, we used knockout mouse models and time-lapse microscopy to elucidate G? and G? subunits contributing to complement C5a receptor-mediated chemotaxis. Complement C5a-mediated chemokinesis and chemotaxis were almost completely abolished in macrophages lacking Gnai2 (encoding G?(i2)), consistent with a reduced leukocyte recruitment previously observed in Gnai2(?/?) mice, whereas cells lacking Gnai3 (G?(i3)) exhibited only a slight decrease in cell velocity. Surprisingly, C5a-induced Ca2+ transients and lamellipodial membrane spreading were persistent in Gnai2(?/?) macrophages. Macrophages lacking both Gnaq (G?(q)) and Gna11 (G?(11)) or both Gna12 (G?(12)) and Gna13 (G?(13)) had essentially normal chemotaxis, Ca2+ signaling, and cell spreading, except Gna12/Gna13-deficient macrophages had increased cell velocity and elongated trailing ends. Moreover, Gnaq/Gna11-deficient cells did not respond to purinergic receptor P2Y(2) stimulation. Genetic deletion of Gna15 (G?(15)) virtually abolished C5a-induced Ca2+ transients, but chemotaxis and cell spreading were preserved. Homozygous Gnb1 (G?(1)) deletion was lethal, but mice lacking Gnb2 (G?(2)) were viable. Gnb2(?/?) macrophages exhibited robust Ca2+ transients and cell spreading, albeit decreased cell velocity and impaired chemotaxis. In summary, complement C5a-mediated chemotaxis requires G?(i2) and G?(2), but not Ca2+ signaling, and membrane protrusive activity is promoted by G proteins that deplete phosphatidylinositol 4,5-bisphosphate.