Abstract
Recent evidence indicates that membrane microdomains, termed lipid rafts, have a role in B-cell activation as platforms for B-cell antigen receptor (BCR) signal initiation. To gain an insight into the possible functioning of lipid rafts in B cells, we applied liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) methodologies to the identification of proteins that co-purified with lipid rafts of Raji cells. Among these raft proteins, we characterized a novel protein termed Raftlin (raft-linking protein). Like the Src family kinase, Raftlin is localized exclusively in lipid rafts by fatty acylation of N-terminal Gly2 and Cys3, and is co-localized with BCR before and after BCR stimulation. Disruption of the Raftlin gene in the DT40 B-cell line resulted in a marked reduction in the quantity of lipid raft components, including Lyn and ganglioside GM1, while overexpression of Raftlin increased the content of raft protein. Moreover, BCR-mediated tyrosine phosphorylation and calcium mobilization were impaired by the lack of Raftlin and actually potentiated by overexpression of Raftlin. These data suggest that Raftlin plays a pivotal role in the formation and/ or maintenance of lipid rafts, therefore regulating BCR-mediated signaling.
| Original language | English |
|---|---|
| Pages (from-to) | 3015-3026 |
| Number of pages | 12 |
| Journal | EMBO Journal |
| Volume | 22 |
| Issue number | 12 |
| DOIs | |
| Publication status | Published - 2003 Jun 16 |
| Externally published | Yes |
Fingerprint
Keywords
- B cell
- BCR
- Lipid raft
- Phosphorylation
ASJC Scopus subject areas
- Genetics
- Cell Biology
Cite this
The B cell-specific major raft protein, Raftlin, is necessary for the integrity of lipid raft and BCR signal transduction. / Saeki, Kazuko; Miura, Yoshiki; Aki, Daisuke; Kurosaki, Tomohiro; Yoshimura, Akihiko.
In: EMBO Journal, Vol. 22, No. 12, 16.06.2003, p. 3015-3026.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - The B cell-specific major raft protein, Raftlin, is necessary for the integrity of lipid raft and BCR signal transduction
AU - Saeki, Kazuko
AU - Miura, Yoshiki
AU - Aki, Daisuke
AU - Kurosaki, Tomohiro
AU - Yoshimura, Akihiko
PY - 2003/6/16
Y1 - 2003/6/16
N2 - Recent evidence indicates that membrane microdomains, termed lipid rafts, have a role in B-cell activation as platforms for B-cell antigen receptor (BCR) signal initiation. To gain an insight into the possible functioning of lipid rafts in B cells, we applied liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) methodologies to the identification of proteins that co-purified with lipid rafts of Raji cells. Among these raft proteins, we characterized a novel protein termed Raftlin (raft-linking protein). Like the Src family kinase, Raftlin is localized exclusively in lipid rafts by fatty acylation of N-terminal Gly2 and Cys3, and is co-localized with BCR before and after BCR stimulation. Disruption of the Raftlin gene in the DT40 B-cell line resulted in a marked reduction in the quantity of lipid raft components, including Lyn and ganglioside GM1, while overexpression of Raftlin increased the content of raft protein. Moreover, BCR-mediated tyrosine phosphorylation and calcium mobilization were impaired by the lack of Raftlin and actually potentiated by overexpression of Raftlin. These data suggest that Raftlin plays a pivotal role in the formation and/ or maintenance of lipid rafts, therefore regulating BCR-mediated signaling.
AB - Recent evidence indicates that membrane microdomains, termed lipid rafts, have a role in B-cell activation as platforms for B-cell antigen receptor (BCR) signal initiation. To gain an insight into the possible functioning of lipid rafts in B cells, we applied liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) methodologies to the identification of proteins that co-purified with lipid rafts of Raji cells. Among these raft proteins, we characterized a novel protein termed Raftlin (raft-linking protein). Like the Src family kinase, Raftlin is localized exclusively in lipid rafts by fatty acylation of N-terminal Gly2 and Cys3, and is co-localized with BCR before and after BCR stimulation. Disruption of the Raftlin gene in the DT40 B-cell line resulted in a marked reduction in the quantity of lipid raft components, including Lyn and ganglioside GM1, while overexpression of Raftlin increased the content of raft protein. Moreover, BCR-mediated tyrosine phosphorylation and calcium mobilization were impaired by the lack of Raftlin and actually potentiated by overexpression of Raftlin. These data suggest that Raftlin plays a pivotal role in the formation and/ or maintenance of lipid rafts, therefore regulating BCR-mediated signaling.
KW - B cell
KW - BCR
KW - Lipid raft
KW - Phosphorylation
UR - http://www.scopus.com/inward/record.url?scp=0038275858&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0038275858&partnerID=8YFLogxK
U2 - 10.1093/emboj/cdg293
DO - 10.1093/emboj/cdg293
M3 - Article
VL - 22
SP - 3015
EP - 3026
JO - EMBO Journal
JF - EMBO Journal
SN - 0261-4189
IS - 12
ER -