LRBA is located on chromosome 4q31.3 and comprises 750,839 bp along 58 exons.
On the other hand, the domain DUF1088 (domain of unknown function 1088) is shared only by LRBA and its paralog neurobeachin, which may indicate specific functions of these two proteins not shared by other members of the BDCP.
In addition to these domains, LRBA seems to contain a VHS domain (VPS (vacuolar protein sorting)-27, Hrs (hepatocyte growth factor-regulated tyrosine kinase sustrate) STAM (signal transducing adaptor molecule) domain) (13).
Remarkably, the LRBA expression is not limited to the immune system, and considerably increases in several cancer tissues (14).
LRBA participates in vesicular trafficking and receptor recycling CTLA-4 (Cytotoxic T-Lymphocyte Antigen 4) is a protein receptor located in the plasmatic membrane of activated T cells.
Other study that demonstrates the LRBA role in vesicular trafficking is related to the epidermal growth factor receptor (EGFR).
Finally, LRBA deficient patients exhibited a decrease in apoptosis mediated by the death receptor Fas, as compared to healthy donors (6).
These evidences suggest that LRBA might be involved in the vesicular trafficking of other receptors in lymphocytes.
As already mentioned, LRBA inhibits the degradation of CTLA-4 in lysosomes by competition with AP1, which suggest that this protein is necessary for mobilization to these compartments (8).
Therefore, studies quantifying the expression of the mentioned receptors in LRBA deficient cells (either by silencing or from patients) are needed.