Ro/SS-A antigen in human platelets. Different distributions of the isoforms of Ro/SS-A protein and the Ro/SS-A-binding RNA.
Ro/SS-A antigen is present in human platelets at a concentration that is approximately one-twentieth to one-thirtieth its concentration in lymphocytes, but the distribution of the Ro/SS-A isoforms is different from that in lymphocytes or red blood cells. The Ro/SS-A in platelets is largely the 52-kd form. Moreover, the 52-kd isoform in platelets is antigenically different from that in lymphocytes. In addition to the varied isoform distribution, a different distribution of the Ro/SS-A-binding RNA (hY RNA) is seen in platelets. While there are 4 hY RNA (hY1, hY3, hY4, and hY5) in lymphocytes and other nucleated cells, we have found that platelets contain only 2 hY RNA: hY3 and hY4. This hY RNA distribution is also different from that in red blood cells, which contain only hY1 and hY4. The different distributions of the Ro/SS-A components in lymphocytes, red blood cells, and platelets suggest different functional roles for the various protein and RNA components, as well as the possibility of different tissue-specific events related to the Ro/SS-A-autoanti-Ro/SS-A system.
Itoh
Y
Y
Arthritis and Immunology Program, Oklahoma Medical Research Foundation, Oklahoma City 73104.
Reichlin
M
M
D001324:Autoantigens / Q000378:metabolism*; D001792:Blood Platelets / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D004912:Erythrocytes / Q000276:immunology; D006801:Humans; D007519:Isoantigens / Q000378:metabolism*; D008214:Lymphocytes / Q000276:immunology; D011485:Protein Binding; D012313:RNA / Q000378:metabolism*; D020733:RNA, Small Cytoplasmic; D012261:Ribonucleoproteins / Q000097:blood* / Q000276:immunology / Q000378:metabolism; D000099207:SS-A Antigen
D001324:Autoantigens; D007519:Isoantigens; D012313:RNA; D020733:RNA, Small Cytoplasmic; D012261:Ribonucleoproteins; D000099207:SS-A Antigen; C116006:RO60 protein, human