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.
Service Régional Vaudois de Transfusion Sanguine, Lausanne, Switzerland.
Françoise
F
Vuadens
Nathalie
N
Rufer
Annegret
A
Kress
Patricia
P
Corthésy
Philippe
P
Schneider
Jean-Daniel
JD
Tissot
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