Plasticity of B cell receptor internalization upon conditional depletion of clathrin.
B cell antigen receptor (BCR) association with lipid rafts, the actin cytoskeleton, and clathrin-coated pits influences B cell signaling and antigen presentation. Although all three cellular structures have been separately implicated in BCR internalization, the relationship between them has not been clearly defined. In this study, internalization pathways were characterized by specifically blocking each potential mechanism of internalization. BCR uptake was reduced by approximately 70% in B cells conditionally deficient in clathrin heavy chain expression. Actin or raft antagonists were both able to block the residual, clathrin-independent BCR internalization. These agents also affected clathrin-dependent internalization, indicating that clathrin-coated pits, in concert with mechanisms dependent on rafts and actin, mediate the majority of BCR internalization. Clustering G(M1) gangliosides enhanced clathrin-independent BCR internalization, and this required actin. Thus, although rafts or actin independently did not mediate BCR internalization, they apparently cooperate to promote some internalization even in the absence of clathrin. Simultaneous inhibition of all BCR uptake pathways resulted in sustained tyrosine phosphorylation and activation of the extracellular signal-regulated kinase (ERK), strongly suggesting that downstream BCR signaling can occur without receptor translocation to endosomes and that internalization leads to signal attenuation.
Stoddart
Angela
A
G. W. Hooper Foundation, University of California San Francisco, San Francisco, CA 94143, USA.
Jackson
Antony P
AP
Brodsky
Frances M
FM
D000199:Actins / Q000378:metabolism; D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism*; D001693:Biological Transport, Active; D002460:Cell Line; D002645:Chickens; D002966:Clathrin / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D004705:Endocytosis; D006801:Humans; D021962:Membrane Microdomains / Q000378:metabolism; D011947:Receptors, Antigen, B-Cell / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
D000199:Actins; D002966:Clathrin; D011947:Receptors, Antigen, B-Cell; D011994:Recombinant Proteins
J Exp Med. 1999 Dec 6;190(11):1549-60
10587346
Mol Biol Cell. 2004 Jul;15(7):3181-95
15133132
J Cell Biol. 2000 May 29;149(5):1131-42
10831616
Trends Cell Biol. 2000 Aug;10(8):343-8
10884687
J Cell Biol. 1980 Oct;87(1):132-41
6968316
Nature. 1985 Apr 11-17;314(6011):537-9
3157869
J Cell Biol. 1985 Dec;101(6):2047-54
2415533
Cell. 1991 Oct 4;67(1):179-88
1913816
Proc Natl Acad Sci U S A. 1992 Jan 1;89(1):114-7
1370346
Cell. 1992 Mar 6;68(5):899-910
1547490
J Histochem Cytochem. 1994 Feb;42(2):155-66
8288861
J Immunol. 1995 Oct 15;155(8):3769-79
7561081
J Cell Biol. 1996 Nov;135(3):635-45
8909539
Science. 1996 Dec 20;274(5295):2086-9
8953040
J Neurosci. 1996 Dec 15;16(24):7950-64
8987823
Annu Rev Immunol. 1997;15:453-79
9143696
J Immunol. 1997 Aug 1;159(3):1096-106
9233602
Science. 1998 Aug 7;281(5378):821-4
9694653
Cell. 1999 Mar 5;96(5):677-87
10089883
J Cell Biol. 1999 Oct 18;147(2):447-61
10525547
J Biol Chem. 2005 Feb 18;280(7):6109-17
15533940
J Immunol. 2001 Feb 1;166(3):1507-16
11160190
Immunity. 2001 Jan;14(1):57-67
11163230
EMBO J. 2001 Jan 15;20(1-2):272-84
11226177
Traffic. 2001 Jun;2(6):414-27
11389769
Mol Cell. 2001 Mar;7(3):661-71
11463390
Annu Rev Cell Dev Biol. 2001;17:517-68
11687498
Neuron. 2001 Dec 6;32(5):801-14
11738027
Science. 2002 Aug 30;297(5586):1521-5
12202821
Mol Cell Biol. 2002 Oct;22(20):7279-90
12242303
J Cell Biol. 2002 Sep 30;158(7):1239-49
12356868
Immunity. 2002 Oct;17(4):451-62
12387739
J Immunol. 2003 Jan 15;170(2):905-12
12517956
Nat Cell Biol. 2003 May;5(5):410-21
12717440
J Exp Biol. 2003 Jun;206(Pt 12):2073-82
12756289
Cell. 2004 Feb 6;116(3):445-56
15016378
J Exp Med. 2004 Apr 5;199(7):981-91
15067034
J Cell Sci. 2000 Mar;113 ( Pt 6):1009-19
10683149