Question

In T cells, which of the following invariant proteins provide the function of transporting the T-cell receptor to the membrane?

1) Igα and Igβ
2) CD4 and CD8
3) MHC class I and MHC class II
4) TCRα and TCRβ

Answer 1

The invariant proteins that transport the T-cell receptor to the membrane are Igα and Igβ.

Step-by-step explanation:

The invariant proteins that provide the function of transporting the T-cell receptor (TCR) to the membrane are known as Igα and Igβ. The TCR, being similar to antibodies in its structure with a variable and a constant region, requires these proteins to anchor it to the membrane of T cells. They are analogous to the immunoglobulin heavy chain signalling subunits found in B cells. CD4 and CD8 are co-receptors that enhance the interaction between T cells and antigen-presenting cells. MHC class I and MHC class II molecules present processed antigens to the T cells but are not involved in transporting the TCR. TCRα and TCRβ are the chains that together form the T-cell receptor but are not responsible for its membrane transport. Hence, the correct answer to the student's question is option 1) Igα and Igβ.