Identification of swiprosin 1 in human lymphocytes.
The aim of this work was to identify a new protein that discriminated CD8 from CD4 and CD19 lymphocytes. Proteins were separated by high-resolution two-dimensional electrophoresis. After silver staining, the gel images were captured with a laser densitometer, and studied with a dedicated software. This study confirmed the presence of two spots that appeared to be preferentially associated with CD8 lymphocytes, and mass spectrometry analyzes (liquid chromatography-tandem mass spectrometry, LC-MS/MS) identified six peptides for one spot and four for the other. The peptide sequences corresponded to an unknown protein that we named swiprosin 1 (Swiss-Prot Q96C19). Molecular analysis (reverse transcriptase-polymerase chain reaction, RT-PCR) and Northern blots confirmed that the gene expression was increased in purified populations of CD8 lymphocytes, when compared to CD19 and CD4 lymphocytes. Database mining revealed that swiprosin 1 contains two potential EF-hand domains, and therefore may have a role in calcium signaling. Its predominant presence in CD8 lymphocytes suggests that it may be involved in functions that are important for cytotoxic lymphocytes.
Vuadens
Françoise
F
Service Régional Vaudois de Transfusion Sanguine, Lausanne, Switzerland.
Rufer
Nathalie
N
Kress
Annegret
A
Corthésy
Patricia
P
Schneider
Philippe
P
Tissot
Jean-Daniel
JD
D000595:Amino Acid Sequence; D018941:Antigens, CD19 / Q000032:analysis; D015704:CD4 Antigens / Q000032:analysis; D018414:CD8-Positive T-Lymphocytes / Q000737:chemistry* / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000032:analysis* / Q000235:genetics; D002853:Chromatography, Liquid; D015180:Electrophoresis, Gel, Two-Dimensional; D006801:Humans; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D011506:Proteins / Q000032:analysis* / Q000235:genetics
D018941:Antigens, CD19; D015704:CD4 Antigens; D002135:Calcium-Binding Proteins; C502299:EFHD2 protein, human; D011506:Proteins