Disease relevance of Cdc42se1

• Mice that express delta SCIP exhibit a debilitating peripheral neuropathy that results from developmentally advanced Schwann cell differentiation, over-expression of myelin-specific gene products, and hypermyelination [1].

High impact information on Cdc42se1

• Unexpectedly, the activation of major myelin-specific genes appears to be unaffected by the Tst-1/Oct-6/SCIP mutation, demonstrating that multiple, independently regulated events are required for terminal differentiation of Schwann cells [2].
• In addition, aberrant differentiation and migration of specific neurons in Tst-1/Oct-6/SCIP mutant homozygotes is associated with a fatal breathing defect, providing a model for investigating the regulation of pulmonary homeostasis [2].
• Following trkB deletion in pyramidal cells, their dendritic arbors are altered, and cortical layers II/III and V are compressed, after which there is an apparent loss of mutant neurons expressing the transcription factor SCIP but not of those expressing Otx-1 [3].
• Nucleotide sequence of mouse SCIP cDNA, a POU-domain transcription factor [4].
• Finally, in situ hybridization and transfection analysis suggests that COUP-TFI acts as an upstream regulator of SCIP/Oct-6/Tst-1, a transcription factor involved in axon myelination [5].

Biological context of Cdc42se1

• Thus, there appears to be a single polymorphic Spec1 gene in the sea urchin genome [6].
• Premature Schwann cell differentiation and hypermyelination in mice expressing a targeted antagonist of the POU transcription factor SCIP [1].
• The Spec1 gene is 10.3 kb in length and contains six exons [6].
• Analysis of sequences within a few kb of the Spec1 gene show that there are five members of a repetitive sequence family near the gene, three upstream and two downstream [6].
• Abnormal nerve conduction studies in mice expressing a mutant form of the POU transcription factor SCIP [7].

Anatomical context of Cdc42se1

• In earlier studies we demonstrated that a small family of messenger RNAs, termed Spec mRNAs for S. purpuratus ectodermal mRNAs, begins to accumulate 20 hours after fertilization in ectoderm cells of the sea urchin embryo [6].
• The transcription factor SCIP is expressed by immature neurons and Schwann cells of the developing central and peripheral nervous systems, but this expression is largely extinguished when these cells fully differentiate [1].
• In multipotent cells isolated from dorsal root ganglia, soluble NRG1 isoforms do not promote Schwann cell features, whereas signaling by membrane-associated NRG1 type III induces the expression of the Schwann cell markers Oct-6/SCIP and S100 in neighboring cells, independent of survival [8].
• Native SCIP is expressed in promyelinating Schwann cells, where it represses expression of the myelin structural genes [7].
• It has been reported that spaceflight conditions alter the immune system and resistance to infection [Belay T, Aviles H, Vance M, Fountain K, and Sonnenfeld G. J Allergy Clin Immunol 170: 262-268, 2002; Hankins WR and Ziegelschmid JF. In: Biomedical Results of Apollo. Washington, DC: NASA, 1975, p. 43-81. (NASA Spec. Rep. SP-368)] [9].

References