Detection of a secreted form of the murine H-2 class I antigen with an antibody against its predicted carboxyl terminus.

AUTOR(ES)

Maloy, W L

RESUMO

Analysis of H-2 class I-specific cDNA clones has suggested the synthesis by the liver of a class I molecule that is secreted rather than membrane bound. To detect this putative class I-related molecule, we have predicted a unique region of amino acid sequence located toward the carboxyl terminus of the molecule that is not expected to be shared with any of the classical H-2 class I antigens, and we have generated specific antibodies to a synthetic peptide corresponding to this sequence. Indirect immunoprecipitation with this antibody led to the identification of a Mr 40,000 polypeptide in association with beta 2-microglobulin in the serum of mice of five different H-2 haplotypes. This class I molecule is also detected in the liver together with lower molecular weight components, which are presumably underglycosylated precursors. Synthesis of this molecule is not detected in thymus, spleen, kidney, or testis. This class I serum component has no detectable reactivity with either a broad-specificity alloantiserum against H-2b or a xenoantiserum against purified H-2a class I molecules. The availability of a specific antibody against the secreted class I molecule offers a means to purify this protein for structural and functional studies.

Documentos Relacionados

• Identification of a second class I antigen controlled by the K end of the H-2 complex and its selective cellular expression.
• Allospecific cytotoxic T lymphocytes recognize an H-2 peptide in the context of a murine major histocompatibility complex class I molecule.
• Tissue-specific expression of an unusual H-2 (class I)-related gene.
• Phosphorylation of the avian retrovirus integration protein and proteolytic processing of its carboxyl terminus.
• Lack of class I H-2 antigens in cells transformed by radiation leukemia virus is associated with methylation and rearrangement of H-2 DNA.