|
|
||||||||
CUTTING EDGE |
,
,
,
*
Department of Biology, Boston College, Chestnut Hill, MA 02467; and Departments of
Medicine and
Microbiology, and
The Evans Memorial Department of Clinical Research, Boston University Medical Center, Boston, MA 02118
B-1 lymphocytes represent a distinct B cell subset with unusual mitogenic responses. PMA alone promotes proliferation in B-1 cells, but not in splenic B-2 cells. Although cyclin D2-cyclin-dependent kinase 4 (cdk4) complexes mediate early retinoblastoma gene product (pRb) phosphorylation in B-1 cells, the transient nature of their accumulation cannot account for the continued increase in pRb phosphorylation, which is maximal at 24 h. We show herein that PMA promotes the accumulation of functional cyclin D3-cdk4 complexes in B-1 cells following loss of cyclin D2. PMA also induces accumulation of cyclin D3-cdk4 complexes in B-2 cells; however, these complexes do not phosphorylate pRb. Thus, PMA is sufficient to induce synthesis and assembly of cyclin D3-cdk4 complexes in B-1 and B-2 cells; however, PMA triggers cyclin D3-cdk4 activation only in B-1 cells. These results reveal a novel regulatory step that controls activation of cyclin D3-cdk4 complexes whose function segregates differentially in B cell subsets.
This article has been cited by other articles:
![]() |
J. M. Mataraza, J. R. Tumang, M. R. Gumina, S. M. Gurdak, T. L. Rothstein, and T. C. Chiles Disruption of Cyclin D3 Blocks Proliferation of Normal B-1a Cells, but Loss of Cyclin D3 Is Compensated by Cyclin D2 in Cyclin D3-Deficient Mice J. Immunol., July 15, 2006; 177(2): 787 - 795. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. A. de la Fuente, L. Kumar, B. Lu, and R. S. Geha 3BP2 Deficiency Impairs the Response of B Cells, but Not T Cells, to Antigen Receptor Ligation. Mol. Cell. Biol., July 1, 2006; 26(14): 5214 - 5225. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. C. Chiles Regulation and Function of Cyclin D2 in B Lymphocyte Subsets J. Immunol., September 1, 2004; 173(5): 2901 - 2907. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. B. Aldrich, W. Chen, M. R. Blackburn, H. Martinez-Valdez, S. K. Datta, and R. E. Kellems Impaired Germinal Center Maturation in Adenosine Deaminase Deficiency J. Immunol., November 15, 2003; 171(10): 5562 - 5570. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. L. Rothstein Two B-1 or Not To Be One J. Immunol., May 1, 2002; 168(9): 4257 - 4261. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |