Investigation of the Mode of Action of Pinn in Epithelial Biogenesis Using Gene-Engineered Mice

Project: National Science and Technology CouncilNational Science and Technology Council Academic Grants

Project Details

Abstract

The opportunity to inactivate specific genes using the classic gene targeting method has significantly accelerated our ability to test gene function. However, not all biological processes can be accessed and studied by gene-inactivation. Classic gene targeting will allow one to identify the initial stage at which the target gene plays a critical role, but not necessarily later. The method of choice for precise gene function analyses in adult mice, however, is the temporal control of gene inactivation as it can prevent impaired embryonic development until the time of induction. In particular, inducible gene targeting in all organs would be a useful tool if the major site of gene action is not precisely defined. For the past several years our group worked on the functional characterization of pinin (pnn), a protein with dual subcellular location. Desmosome pnn was implicated in cell-cell adhesion while nuclear pnn involved in mRNA splicing. Homozygous pnn deficient mice died at early embryonic stage, suggesting a role of pnn in embryonic development (manuscript submitted to JCB and under revision, see appendix). In addition, recent studies indicated that Pnn is highly expressed in epidermis of either developing mouse embryos or adult mice (Leu and Ouyang, 2006) and transgenic (Tg) mice overexpressing pnn under keratin 14 (k14) promoter displayed hyperproliferative defect in complex epithelia including skin and esophagus. To address pnn’s function under keratinocyte growth/differentiation context, we will examine the molecular mechanism responsible for defected morphology in k14-pnn Tg mice and will also present plans to generate mice homozygous deficient for pnn in a temporally controlled manner through intercrossing inducibly expressed keratin 5Cre-ER transgenic with mouse harboring pnnflox gene. pnnflox mice will be generated based on three lox P sites-containing targeting vector. The inducible pnn ko mice will be selected to evaluate effects of loss of this protein on phenotypical presentation of complex epithelia and to assay pnn’s function in complex epithelia morphogenesis. Finally with these pnn mouse models, we will examine the co-operating molecules associated with pnn dysfunction from global protein and gene expression/splicing profiling through proteomic analysis and microarray/exon splicing assay.

Project IDs

Project ID:PC10001-0102
External Project ID:NSC98-2320-B182-019-MY3
StatusFinished
Effective start/end date01/08/1131/07/12

Keywords

  • Pnn
  • keratinocyte
  • esophagus
  • condition ablation

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