CD8α deficiency

Gene Information


HUGO name: CD8A


  • CD8
  • MAL
  • p32
  • CD8 antigen, alpha polypeptide
  • T-cell surface glycoprotein CD8 alpha chain precursor
  • T-lymphocyte differentiation antigen T8/Leu-2


Reference sequences

Chromosomal location


Protein Information


Protein function:

Identifies cytotoxic/suppressor T-cells that interact with MHC class I bearing targets. CD8 is thought to play a role in the process of T-cell mediated killing. CD8 alpha chains binds to class I MHC molecules alpha-3 domains.


In general heterodimer of an alpha and a beta chain linked by two disulfide bonds. Can also form homodimers.

Subcellular location:

Type I membrane protein

Post-translational modification:

All of the five most carboxyl-terminal cysteines are used to form inter-chain disulfide bonds in dimers and higher multimers, while the four amino-terminal cysteines are not.

Alternative products:

Various patterns of differential splicing of CD8 alpha transcripts involve excision of the transmembrane or cytoplasmic domains.

Structures (PDB)

1CD8 Crystal structure of a soluble form of the human T cell coreceptor CD8 at 2.6 A resolution.


Extracellular domain: 22-182

    Cytoplasmic domain: 204-235

      Ig-like v-type domain domain: 22-135

        Other features

        Signal peptide: 1-21

          T-cell surface glycoprotein cd8 alpha chain: 22-235

            Disulfide bond: 43-115

              Other related resourses:


              Expression pattern for human

              Tissue Expression (%) Clones
              blood, white cells 38.59 1:910
              thymus, pooled 22.16 2:3169
              leukocyte 15.64 4:8982
              mixed 5.24 9:60341
              kidney, pooled 4.74 1:7404
              parathyroid 4.11 2:17083
              germ cell, pooled 2.94 3:35870
              unclassified 2.03 3:51898
              prostate 1.39 3:76067
              ovary 0.74 1:47578