Expression and Functional Analysis of a Novel Isoform of Gicerin, an Immunoglobulin Superfamily Cell Adhesion Molecule ()

• Published in: The Journal of biological chemistry Vol. 270; no. 48; pp. 28681 - 28687
• Main Authors: Taira, Eiichi, Nagino, Tomoko, Taniura, Hideo, Takaha, Natsuki, Kim, Cheol-Hee, Kuo, Che-Hui, Li, Bing-Shen, Higuchi, Hiroshi, Miki, Naomasa
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.12.1995; American Society for Biochemistry and Molecular Biology
• Subjects: Amino Acid Sequence; Animals; Avian Proteins; Base Sequence; Blotting, Western; Carrier Proteins - chemistry; Carrier Proteins - genetics; Carrier Proteins - physiology; CD146 Antigen; Cell Adhesion - genetics; Cell Adhesion Molecules - chemistry; Cell Adhesion Molecules - genetics; Cell Adhesion Molecules - physiology; Cell Aggregation - genetics; Cell Line; Chick Embryo; Chickens; DNA Primers - chemistry; DNA, Complementary; Ganglia - embryology; Genes, Immunoglobulin; Mice; Molecular Sequence Data; Nerve Tissue Proteins - chemistry; Nerve Tissue Proteins - genetics; Nerve Tissue Proteins - physiology; Nervous System - embryology; Neurites; Transfection
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.270.48.28681

We have cloned a novel cDNA of gicerin, a cell adhesion molecule belonging to the immunoglobulin superfamily. Both gicerin isoforms share the same extracellular domain, which has five immunoglobulin-like loop structures and a transmembrane domain as s-gicerin, but differ in the cytoplasmic tail domain. As the newly identified form has a larger cytoplasmic domain than the previously reported form, we refer to them as l-gicerin and s-gicerin, respectively. l-gicerin is transcribed from a distinct mRNA containing an inserted sequence not found in s-gicerin mRNA which caused a frameshift for the coding region for a cytoplasmic domain. Previous studies demonstrated that gicerin showed a doublet band of 82 and 90 kDa in chicken gizzard smooth muscle. We report that the 82-kDa protein corresponds to s-gicerin and the 90-kDa protein to l-gicerin. We also found that the two gicerin isoforms are expressed differentially in the developing nervous system. Functional analysis of these gicerin isoforms in stable transfectants revealed that they had differ in their homophilic adhesion properties, as well as in heterophilic cell adhesion assayed with neurite outgrowth factor. In addition, these isoforms have neurite-promoting activity by their homophilic adhesion, but differ in their ability to promote neurite outgrowth.