Region-specific neuroastroglial interactions in neuronal morphogenesis and polarity: from homeogenic induction to cellular cytomechanics.
Because of several studies on neuronal differentiation, it has been possible to produce a list of adhesion molecules, cytoskeletal elements, and transacting factors that participate in the determination of neuronal shape and polarity. Most of these proteins are ubiquitous, and this lack of regional specificity is unlikely to be compensated for by editing mechanisms, such as alternative splicing and post-translational modifications. In this context it is quite difficult to understand the regional specificity of neuroneuronal or neuroastroglial interactions. For this reason, we are interested in the study of homeoproteins, a class of transcription factors endowed with regional specificity, which regulate the synthesis of several morphoregulatory molecules, including cell and substrate adhesion molecules. We propose a model in which specific neuroastroglial and neuroneuronal interactions result from the homeoprotein-dependent regulation of the quantities and of the topological organization of such ubiquitous morphoregulatory molecules. Moreover, we extend this model by proposing that some homeoprotein isoforms could act not only according to a classic intracrine mode, but also through a paracrine mechanism.
CNRS URA 1414, Ecole Normale Supérieure, Paris, France.
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D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000502:physiology*; D001369:Axons / Q000502:physiology; D002448:Cell Adhesion; D002450:Cell Communication; D002454:Cell Differentiation; D003712:Dendrites / Q000502:physiology; D005801:Genes, Homeobox; D006025:Glycosaminoglycans / Q000502:physiology; D018398:Homeodomain Proteins / Q000096:biosynthesis / Q000502:physiology*; D006801:Humans; D008959:Models, Neurological; D009024:Morphogenesis; D005810:Multigene Family; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D011509:Proteoglycans / Q000502:physiology
D006025:Glycosaminoglycans; D018398:Homeodomain Proteins; D011509:Proteoglycans