G protein subunit G alpha 16 expression is restricted to progenitor B cells during human B-cell differentiation.

Abstract

Recently G alpha 16, a new guanosine triphosphate (GTP) binding protein alpha subunit has been described to be specifically expressed in human hematopoietic cells. Expression of G alpha 16 was observed in human cell lines of myelomonocytic and T-lymphocytic origin, but not in human B-cell lines Raji and IM9. We studied the expression of G alpha 16 in human B cells corresponding to different stages of B-cell differentiation by means of reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blotting. The human Burkitt's lymphoma cell lines Raji, Ramos, BJAB, the lymphoblastoid cell line SKW6.4, and the plasmocytoma cell line U266 were devoid of G alpha 16. In contrast, G alpha 16 was detected in the human progenitor B cell lines Reh and Nalm-6. Using the mu+, k- cell line BLIN-1 (pre-B cell phenotype) and its derived subclone 1E8 (surface mu+, k+; B-cell phenotype) G alpha 16 expression was found to disappear on transition from pre-B to B-cell differentiation stage. The analysis of a broad panel of human neoplastic B lymphocytes ranging from progenitor B-acute lymphatic leukemia (pre-pre-B-ALL), common acute leukemias (cALL), pre-B-ALL, mature B-ALL to low grade B-cell lymphoma (chronic lymphocytic leukemia of B-cell type, leukemic centrocytic non-Hodgkins lymphoma [NHL], hairy cell leukemia) showed that G alpha 16 expression is limited to progenitor and pre-B-ALL cells. Therefore, we conclude that within B-cell differentiation, G alpha 16 is expressed solely during early B cell ontogeny and downregulated during differentiation. Thus, G alpha 16 might be an important regulator involved in signaling processes in progenitor B cells.

• Authors: M Y Mapara, K Bommert, R C Bargou, C Leng, C Beck, W D Ludwig, P Gierschik, B Dörken
• Journal: Blood (Blood) Vol. 85 Issue 7 Pg. 1836-42 (Apr 01 1995) ISSN: 0006-4971 [Print] United States
• PMID: 7703490 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Neoplasm Proteins
• Receptors, Antigen, B-Cell
• GTP-Binding Proteins

Topics

• B-Lymphocytes (metabolism, pathology)
• Base Sequence
• Burkitt Lymphoma (genetics, pathology)
• Cell Differentiation
• GTP-Binding Proteins (biosynthesis, chemistry, genetics)
• Gene Expression Regulation, Leukemic
• Gene Expression Regulation, Neoplastic
• Humans
• Immunophenotyping
• Leukemia, B-Cell (genetics, pathology)
• Leukemia, Hairy Cell (genetics, pathology)
• Leukemia, Lymphocytic, Chronic, B-Cell (genetics, pathology)
• Leukemia, Promyelocytic, Acute (genetics, pathology)
• Lymphoma, Non-Hodgkin (genetics, pathology)
• Molecular Sequence Data
• Neoplasm Proteins (biosynthesis, chemistry, genetics)
• Neoplastic Stem Cells (metabolism, pathology)
• Plasmacytoma (genetics, pathology)
• Precursor B-Cell Lymphoblastic Leukemia-Lymphoma (genetics, pathology)
• Protein Conformation
• Receptors, Antigen, B-Cell (physiology)
• Signal Transduction
• Tumor Cells, Cultured