Expression Patterns of LRR and Ig domain-containing proteins(LRRIg poteins) in the Early Mouse Embryo

Research Project

Project/Area Number	17500234
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Nerve anatomy/Neuropathology
Research Institution	Fukushima Medical University
Principal Investigator	HOMMA Shunsaku Fukushima Medical University, Dept. of Anatomy, Lecturer (20261795)
Project Period (FY)	2005 – 2006
Project Status	Completed (Fiscal Year 2006)
Budget Amount *help	¥3,600,000 (Direct Cost: ¥3,600,000) Fiscal Year 2006: ¥1,300,000 (Direct Cost: ¥1,300,000) Fiscal Year 2005: ¥2,300,000 (Direct Cost: ¥2,300,000)
Keywords	leucine-rich repeats / Phvlogenetic analysis / dendrogram / immunoglobulin superfamily / in situ hybridization / adhesion molecule / mouse / embryo / Immunoglobulin / 脊髄神経節 / 一次球心性繊維 / 免疫組織化学 / Ig / 一次球心性線維 / 運動ニューロン / in situ hybridization / 脊髄 / ニワトリ胚
Research Abstract	A novel class of the immunoglobulin superfamily, which has recently been identified, involves a group of proteins that simultaneously possess leucine-rich repeats (LRR) and immunoglobulin-like (Ig) domains in their architecture and are termed the leucine-rich repeats and Ig domain-containing protein family (LRRIG protein family). Given the significant biological roles of this new protein family, we have searched the public database and have obtained a comprehensive list of members of the LRRIG protein family. The list includes 35 human proteins: three Trk neurotrophin receptors, four LINGO, three NGL, three LRIG, two GPCR, five SALM, three AMIGO, three NLRR, three Pal, two ISLR, one peroxidasin homolog, two Adlican, and a yet unnamed protein, AAI11068. Based upon the amino acid sequences, the human LRRIG proteins were subdivided into four subclasses: the LINGO/NGL subclass; the subclass of proteins containing an additional fibronectin (FN) domain; the subclass of proteins with multiple Ig domains; and the AMIGO subclass. We then studied the mRNA expression patterns of mouse homologs of these human proteins in embryonic day 10 (E10) mice. Some molecules in the LINGO/NGL and the FN domain-containing subclasses were expressed exclusively in neuronal tissues and some molecules in the FN domain-containing and the multiple Ig domains-containing subclasses exhibited non-neuronal expression profiles. However, the majority of LRRIG protein family members exhibited broad mRNA tissue-expression profiles. These LRRIG mRNA expression patterns may reflect the composite nature of domain architecture favorable to versatile protein-protein interactions.