Sarcolectin (SCL): Structure and expression of the recombinant molecule

• Published in: Biochimie Vol. 81; no. 7; pp. 709 - 715
• Main Authors: Kaba, Aboubacar, Jiang, Pan Hong, Chany-Fournier, Françoise, Chany, Charles
• Format: Journal Article
• Language: English
• Published: France Elsevier Masson SAS 01.07.1999
• Subjects: Amino Acid Sequence; Animals; Base Sequence; Cattle; Cell Line; DNA, Complementary; Humans; Lectins - chemistry; Lectins - genetics; Mice; Molecular Sequence Data; Protein Conformation; recombinant DNA; Recombinant Proteins - chemistry; Recombinant Proteins - genetics; Reverse Transcriptase Polymerase Chain Reaction; SCL; sequence; sequence; recombinant DNA; SCL
• ISSN: 0300-9084; 1638-6183
• DOI: 10.1016/S0300-9084(99)80128-X

Interferons (IFNs) are major cytokines, responsible for down-regulating cell growth and for promoting cell differentiation. The sarcolectin (SCL) protein presented here blocks in the cells the established IFN-dependent interphase and stimulates DNA synthesis, probably in co-ordination with more specific growth factors or hormones. The SCL-DNA structure is closely related to that of cytokeratine K2C7 intermediate filaments, but the SCL is a monomer, or sometimes a dimer, which is excreted into the serum, where it is frequently bound to albumin. Its specific biological functions are carried by the β sheets, and can be found on the two terminal domains of the molecule, the lectinic properties being located mainly on the N-terminus. The recombinant SCL molecule possesses the same biological functions as the native one, since it inhibits the IFN-dependent antiviral state both in human and in mouse cell cultures. On the contrary, antibodies raised against amino acids 41–55 located on the N-terminal domain of SCL inhibit this antagonistic effect. We postulate that the IFN and SCL proteins, because of their opposite biological functions, are in balance and are part of a feedback system operating the regulation of normal growth. In pathological cases, SCL could play a role in the development of tumors, as we have found in juvenile osteosarcomas or in AIDS cases.