A major myristylated substrate of protein kinase C and protein kinase C itself are differentially regulated during murine B- and T-lymphocyte development and activation.
The regulation and expression of protein kinase C (PKC) and phosphomyristin C (PMC) (a principal substrate of PKC which is the major myristylated protein in lymphocyte and glioma lines that express it) in murine B and T lymphocytes were investigated. Both PMC and PKC are differentially regulated during T-cell development. The level of PMC expression is highest in CD4-8-, intermediate in CD4+8+, and lowest in J11d-, CD4, or CD8 single-positive thymocytes. PKC is equally expressed by all three thymic populations. In striking contrast to thymocytes, resting peripheral lymph node T cells and T-cell clones express little if any PMC and reduced levels of PKC. Neither PKC nor PMC is significantly induced upon the activation of lymph node T cells: treatment with anti-CD3 antibodies or anti-CD3 and interleukin-2 fails to induce PKC, whereas PMC is not induced by anti-CD3 alone and is only slightly induced by anti-CD3 and interleukin-2. In contrast to the situation with T cells, PMC and PKC are constitutively expressed at moderate levels in mature B cells. PMC is greatly increased in B-cell blasts generated by cross-linking the antigen receptor with anti-immunoglobulin. These results demonstrate that PMC and PKC are differentially regulated during the development and activation of B and T cells, suggesting that cellular events that rely upon PKC and PMC may differ during ontogeny and activation of different lymphocyte subsets.
Hornbeck
P
P
Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland 20892.
Nakabayashi
H
H
Fowlkes
B J
BJ
Paul
W E
WE
Kligman
D
D
D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism; D002460:Cell Line; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D019814:Myristic Acid; D009227:Myristic Acids / Q000378:metabolism; D000076250:Myristoylated Alanine-Rich C Kinase Substrate; D010750:Phosphoproteins / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism*; D051381:Rats; D015398:Signal Transduction; D013379:Substrate Specificity; D013601:T-Lymphocytes / Q000378:metabolism
D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D009227:Myristic Acids; D010750:Phosphoproteins; D019814:Myristic Acid; D000076250:Myristoylated Alanine-Rich C Kinase Substrate; D011493:Protein Kinase C