ANALYSIS OF THE EXPRESSION OF 7-G PROTEIN ALPHA-SUBUNIT GENES IN HEMATOPOIETIC-CELLS

Various heterotrimeric GTP-binding proteins may have important functio ns in hematopoietic cells. There has been no comprehensive information , however, regarding their expression in various-lineage hematopoietic cells. In this report, the expression level of seven G protein alpha subunits (Gsalpha, Gi1alpha, Gi2alpha, Gi3alpha, Goalpha-1, Goalpha-2, and Gxalpha) in 13 hematopoietic cell lines were analyzed by Northern blot analysis. Gi1alpha, Goalpha-1, Goalpha-2, and Gxalpha, were expr essed in a limited number of cell lines whereas Gsalpha, Gi2alpha, and Gi3alpha were expressed ubiquitously in nearly all cell lines tested. Gi1alpha was expressed selectively in a pre-T cell line, P30/PHK amon g lymphoid-lineage cell lines and a myeloblastic cell line, KG-1 among myelomonocytoid cell lines. Goalpha-1 was expressed only in a chronic myelocytic-leukemia cell line, K-562, whereas Goalpha-2 2 was not exp ressed in any cell lines tested after ordinary exposure of autoradiogr aphy (within 4 days). Gxalpha was expressed abundantly in a rat basoph ilic-leukemia cell line, RBL-2H3, and expressed in K-562. A barely det ectable amount of Gxalpha messenger ribonucleic acid (mRNA) was found after a long exposure of autoradiography in several cell lines with me gakaryoblastoid phenotype.