Identification and tissue expression of a splice variant for the growth arrest-specific gene gas6

The growth arrest-specific gene gas6 encodes a secreted protein (Gas6) which is a member of the vitamin K-dependent protein family and was identified as a ligand for the Ax1 tyrosine kinase receptor family. Gas6 shares significant similarity with protein S and a similar domain organisation: an extensively gamma-carboxylated amino-terminal, four epidermal growth factor-like motifs and a large carboxy-terminal region, known as the D domain. Here we report on the isolation of a splice variant (gas6SV) characterised by an in-frame 129 bp insertion between the fourth EGF domain and the D domain. The gene gas6 was previously mapped on chromosome 13. The genomic organisation of gas6 has been investigated demonstrating the presence of alternative splicing consensus sites. Expression of gas6SV has been investigated in various human tissues and found to have a similar distribution pattern as gas6, with the exception of the spleen where gas6SV seems to be the predominant form.