For each of the descriptions in questions ,select the B cell signaling molecule (A-I)that most closely matches it.
-A protein that covalently binds to microbes and serves as a ligand for a coreceptor that enhances B cell responses to antigen
A)Iga
B)Igb
C)C3b
D)C3d
E)CR2
F)CD19
G)CD81
H)Fyn
I)Syk

Question

Quizplus · Accepted Answer

C3d is a complement protein fragment that binds covalently to microbial surfaces.C3d serves as the link between the BCR,which binds directly to the microbe,and the CR2 coreceptor.This cross-linking between the BCR and CR2 serves to amplify the B cell response 1000-fold when compared with immune responses in which CR2 is not recruited.CR2 forms a complex with two other proteins,CD19 and CD81,on the B cell surface.When CD19 is brought into proximity with BCR-associated kinases,the cytoplasmic tail of CD19 is rapidly phosphorylated.CD19 then activates several signaling pathways,including PI3-kinase.

For Each of the Descriptions in Questions ,Select the B