TY  - JOUR
U1  - Zeitschriftenartikel, wissenschaftlich - begutachtet (reviewed)
A1  - Solomon, Samuel
A1  - Masilamani, Madhan
A1  - Rajendran, Lawrence
A1  - Bastmeyer, Martin
A1  - Stuermer, Claudia A. O.
A1  - Illges, Harald
T1  - The lipid raft microdomain-associated protein reggie-1/flotillin-2 is expressed in human B cells and localized at the plasma membrane and centrosome in PBMCs
JF  - Immunobiology
N2  - Reggie-1/flotillin-2 is a plasma membrane-associated cytoplasmic protein, which defines non-caveolar raft microdomains. Reggie-1/flotillin-2 is enriched in detergent insoluble (TX100) membrane fractions (DIG), co-localizes with activated GPI-linked proteins and the fyn-kinase in neurons and T cells, and thus apparently participates in the assembly of protein complexes essential for signal transduction. In T cells activated by crosslinking the GPI-linked protein Thy-1 or by crosslinking the ganglioside GM1, reggie-1/flotillin-2 co-localizes with the T cell receptor. To determine whether reggie-1/flotillin-2 is also expressed in B cells, primary B cells from human blood and cell lines representing the developmental stages of pro, pre, mature and plasma B cells were analyzed by Western blotting, RT-PCR and immunofluorescence. Here, we show that reggie-1/flotillin-2 is expressed throughout B cell development, as well as in primary B cells, purified by cell sorting. On non-activated mature B cell Raji cell line we found reggie-1/flotillin-2 are exclusively in the detergent (TX100) insoluble membrane fractions that are staining positive for the raft marker GM1. Immunofluorescence microscopy showed that reggie-1/flotillin-2 is localized at the plasma membrane and marks intracellular spots in PBMCs. Confocal co-localization studies showed that reggie-1/flotillin-2 is associated with the plasma membrane, and the centrosomes (microtubule organizing centers) in these PBMCs. Comparison of reggie-1/flotillin-2 cDNA sequences with the genomic sequence database allowed us to determine the exon/intron structures in mouse and human. The gene organizations are highly conserved suggesting an important function of reggie-1/flotillin-2. Since reggie/flotillin proteins co-cluster with the T cell receptor and fyn kinases upon T cell stimulation, our findings of reggie-1/flotillin-2 in B cells suggest a similar role in B cell function.
Y1  - 2002
SN  - 0171-2985
SS  - 0171-2985
U6  - https://doi.org/10.1078/0171-2985-00114
DO  - https://doi.org/10.1078/0171-2985-00114
PM  - 11999340
VL  - 205
IS  - 1
SP  - 108
EP  - 119
PB  - Urban & Fischer
ER  -