title: Toward comprehensive analysis of the galectin network in chicken: unique diversity of galectin-3 and comparison of its localization profile in organs of adult animals to the other four members of this lectin family.
abstract: Characterization of all members of a gene family established by gene divergence is essential to delineate distinct or overlapping expression profiles and functionalities. Their activity as potent modulators of diverse physiological processes directs interest to galectins (endogenous lectins with β-sandwich fold binding β-galactosides and peptide motifs), warranting their study with the long-term aim of a comprehensive analysis. The comparatively low level of complexity of the galectin network in chicken with five members explains the choice of this organism as model. Previously, the three proto-type chicken galectins CG-1A, CG-1B, and CG-2 as well as the tandem-repeat-type CG-8 had been analyzed. Our study fills the remaining gap to determine gene structure, protein characteristics and expression profile of the fifth protein, that is, chimera-type chicken galectin-3 (CG-3). Its gene has a unique potential to generate variants: mRNA production stems from two promoters, alternative splicing of the form from the second transcription start point (tsp) can generate three mRNAs. The protein with functional phosphorylation sites in the N-terminus generated by transcription from the first tsp (tsp1CG-3) is the predominant CG-3 type present in adult tissues. Binding assays with neoglycoproteins and cultured cells disclose marked similarity to properties of human galectin-3. The expression and localization profiles as well as proximal promoter regions have characteristic features distinct from the other four CGs. This information on CG-3 completes the description of the panel of CGs, hereby setting the stage for detailed comparative analysis of the entire CG family, e.g., in embryogenesis.
authors.affiliation: Faculty of Veterinary Medicine, Institute of Physiological Chemistry, Ludwig-Maximilians-University, Veterinärstrasse 13, Munich, Germany. Kaltner@lmu.de
authors.forename: Herbert
authors.initials: H
authors.lastname: Kaltner
authors.forename: Dieter
authors.initials: D
authors.lastname: Kübler
authors.forename: Lara
authors.initials: L
authors.lastname: López-Merino
authors.forename: Michaela
authors.initials: M
authors.lastname: Lohr
authors.forename: Joachim C
authors.initials: JC
authors.lastname: Manning
authors.forename: Martin
authors.initials: M
authors.lastname: Lensch
authors.forename: Joerg
authors.initials: J
authors.lastname: Seidler
authors.forename: Wolf D
authors.initials: WD
authors.lastname: Lehmann
authors.forename: Sabine
authors.initials: S
authors.lastname: André
authors.forename: Dolores
authors.initials: D
authors.lastname: Solís
authors.forename: Hans-Joachim
authors.initials: HJ
authors.lastname: Gabius
mesh_terms: D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002645:Chickens / Q000235:genetics*; D003001:Cloning, Molecular; D037502:Galectin 3 / Q000145:classification / Q000235:genetics*; D020869:Gene Expression Profiling; D006023:Glycoproteins / Q000378:metabolism; D006801:Humans; D007124:Immunoenzyme Techniques; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D037502:Galectin 3; D006023:Glycoproteins; D012333:RNA, Messenger