Background：B-lymphocyte antigen CD19 is also known as CD19 (Cluster of Differentiation 19), is a single-pass type I membrane protein which contains two Ig-like C2-type (immunoglobulin-like) domains.
CD19 is expressed on follicular dendritic cells and B cells.
In fact, it is present on B cells from earliest recognizable B-lineage cells during development to B-cell blasts but is lost on maturation to plasma cells.
It primarily acts as a B cell co-receptor in conjunction with CD21 and CD81.
Upon activation, the cytoplasmic tail of CD19 becomes phosphorylated, which leads to binding by Src-family kinases and recruitment of PI-3 kinase.
As on T cells, several surface molecules form the antigen receptor and form a complex on B lymphocytes.
The (almost) B cell-specific CD19 phosphoglycoprotein is one of these molecules.
The others are CD21 and CD81.
These surface immunoglobulin (sIg)-associated molecules facilitate signal transduction.
On living B cells, anti-immunoglobulin antibody mimicking exogenous antigen causes CD19 to bind to sIg and internalize with it.
The reverse process has not been demonstrated, suggesting that formation of this receptor complex is antigen-induced.
This molecular association has been confirmed by chemical studies.
Mutations in CD19 are associated with severe immunodeficiency syndromes characterized by diminished antibody production.
CD19 has been shown to interact with: CD81, CD82, Complement receptor 2, and VAV2.
仕様
サイズ：100ug
Source：Human CD89, His Tag (CD9-H52Ha) is expressed from human 293 cells (HEK293). It contains AA Gln 22 - Asn 227 (Accession # P24071-1).
Molecule：CD89
Synonyms：CD89,FCAR,IgA Fc receptor
Species：Human
Tag：His Tag
Expression Systems：HEK293
Expression Rigeion：Gln 22 - Asn 227
Conjugate：Unconjugated
Accession：NP_001991.1
Molecular Weight：25.4 kDa
Characteristics：This protein carries a polyhistidine tag at the C-terminus. The protein has a calculated MW of 25.4 kDa. The protein migrates as 38-55 kDa under reducing (R) condition (SDS-PAGE) due to glycosylation.
Endotoxin Level：Less than 1.0 EU per ug by the LAL method.
