Title

Molecular diversity of Dscam and self-recognition

UMMS Affiliation

Department of Neurobiology; Tzumin Lee Lab; Graduate School of Biomedical Sciences, Neuroscience Program

Publication Date

3-7-2012

Document Type

Book Chapter

Subjects

Animals; *Cell Adhesion Molecules; *Cell Communication; Drosophila Proteins; Gene Expression Regulation; Neurons; Protein Isoforms

Disciplines

Neuroscience and Neurobiology

Abstract

Cell recognition requires interactions through molecules located on cell surface. The insect homolog of Down syndrome cell adhesion molecule (Dscam) manifests huge molecular diversity in its extracellular domain. High-affinity Dscam-Dscam interactions only occur between isoforms that carry identical extracellular domains. Homophilic Dscam signaling can, thus, vary in strength depending on the compositions of Dscams present on the opposing cell surfaces. Dscam abundantly exists in the developing nervous system and governs arborization and proper elaboration of neurites. Notably, individual neurons may stochastically and dynamically express a small subset of Dscam isoforms such that any given neurite can be endowed with a unique repertoire of Dscams. This allows individual neurites to recognize their sister branches. Self-recognition leads to self-repulsion, ensuring divergent migration of sister processes. By contrast, weak homophilic Dscam interactions may promote fasciculation of neurites that express analogous, but not identical, Dscams. Differential Dscam binding may provide graded cell recognition that in turn governs complex neuronal morphogenesis.

Rights and Permissions

Citation: Adv Exp Med Biol. 2012;739:262-75. Link to article on publisher's site

Journal/Book/Conference Title

Advances in experimental medicine and biology

Comments

Co-author Lei Shi is a student in the Neuroscience program in the Graduate School of Biomedical Sciences (GSBS) at UMass Medical School.

Related Resources

Link to Article in PubMed

PubMed ID

22399408