Prototype chicken galectins revisited: characterization of a third protein with distinctive hydrodynamic behaviour and expression pattern in organs of adult animals.
Prototype galectins are versatile modulators of cell adhesion and growth via their reactivity to certain carbohydrate and protein ligands. These functions and the galectins' marked developmental regulation explain their attractiveness as models to dissect divergent evolution after gene duplication. Only two members have so far been assumed to constitute this group in chicken, namely the embryonic muscle/liver form {C-16 or CLL-I [16 kDa; chicken lactose lectin, later named CG-16 (chicken galectin-16)]} and the embryonic skin/intestine form (CLL-II or C-14; later named CG-14). In the present study, we report on the cloning and expression of a third prototype CG. It has deceptively similar electrophoretic mobility compared with recombinant C-14, the protein first isolated from embryonic skin, and turned out to be identical with the intestinal protein. Hydrodynamic properties unusual for a homodimeric galectin and characteristic traits in the proximal promoter region set it apart from the two already known CGs. Their structural vicinity to galectin-1 prompts their classification as CG-1A (CG-16)/CG-1B (CG-14), whereas sequence similarity to mammalian galectin-2 gives reason to refer to the intestinal protein as CG-2. The expression profiling by immunohistochemistry with specific antibodies discerned non-overlapping expression patterns for the three CGs in several organs of adult animals. Overall, the results reveal a network of three prototype galectins in chicken.
Kaltner
Herbert
H
Institut für Physiologische Chemie, Tierärztliche Fakultät, Ludwig-Maximilians-Universität München, Veterinärstr. 13, D-80539 München, Germany.
Solís
Dolores
D
Kopitz
Jürgen
J
Lensch
Martin
M
Lohr
Michaela
M
Manning
Joachim C
JC
Mürnseer
Michael
M
Schnölzer
Martina
M
André
Sabine
S
Sáiz
José Luis
JL
Gabius
Hans-Joachim
HJ
D000595:Amino Acid Sequence; D000818:Animals; D030161:Avian Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D002645:Chickens / Q000378:metabolism*; D003001:Cloning, Molecular; D037161:Galectins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D020869:Gene Expression Profiling; D008969:Molecular Sequence Data; D020836:Protein Structure, Quaternary; D013045:Species Specificity
D030161:Avian Proteins; D037161:Galectins