Recombinant Mouse Desmoglein-1-gamma (Dsg1c), partial

Basic Research Questions

• What is Mouse Desmoglein-1-gamma (Dsg1c) and how does it differ from other mouse desmogleins?

  Mouse Desmoglein-1-gamma (Dsg1c), also known as Dsg6 or dsg1g, is a member of the cadherin family of proteins that forms an integral transmembrane component of desmosomes . It belongs to the desmoglein subfamily, which participates in cell-cell adhesion mechanisms in epithelial tissues.

  Dsg1c differs from other mouse desmogleins in several ways:

  • Structural differences: While all mouse desmogleins contain a signal sequence (21 residues), the extracellular (EC) domains, transmembrane region, and intracellular components, Dsg1c/Dsg6 contains four repeat unit domains, compared to five repeats in Dsg1 and Dsg5 .

  • Expression pattern: Dsg1c shows a more restricted expression profile than Dsg2 (which is expressed in all tissues tested). It is primarily expressed in epidermis and liver, while not being detected in heart, whole brain, spleen, lung, skeletal muscle, kidney, or testis .

  • Molecular characteristics: The EA (extracellular anchor) domain demonstrates the least homology between different mouse desmoglein isoforms, making it an ideal target for isoform-specific antibody development .

• What are the optimal methods for detecting Mouse Desmoglein-1-gamma in experimental samples?

  For optimal detection of Mouse Desmoglein-1-gamma, several methodologies can be employed depending on your research objectives:

  • ELISA: Quantitative measurement of Dsg1c can be performed using specific ELISA kits with a detection range of 0.156-10 ng/ml. This colorimetric assay is suitable for tissue homogenates, cell lysates, and other biological fluids .

  • Sample preparation considerations: For accurate results, sample concentrations should be diluted to mid-range of the detection kit. Native samples typically yield better results than recombinant proteins, as kits are optimized for detection of proteins with native tertiary structure .

  • RT-PCR: For transcript detection, gene-specific primers can be employed. When designing primers, target unique regions to distinguish between highly homologous desmoglein isoforms .

  • Immunohistochemistry considerations: When performing antibody-based detection, target the EA domain which shows the least homology between different mouse isoforms, allowing for specific detection of Dsg1c .

• In which tissues and developmental stages is Mouse Desmoglein-1-gamma expressed?

  Mouse Desmoglein-1-gamma (Dsg1c/Dsg6) shows a specific tissue expression pattern:

  Tissue	Dsg1	Dsg2	Dsg3	Dsg4	Dsg5	Dsg6 (Dsg1c)
  Epidermis	+	+	+	+	+	+
  Heart	-	+	-	-	-	-
  Whole brain	-	+	-	-	-	-
  Spleen	-	+	-	-	-	-
  Lung	-	+	-	-	-	-
  Liver	-	+	-	-	-	+
  Skeletal muscle	-	+	-	-	-	-
  Kidney	-	+	-	-	-	-
  Testis	+	+	-	-	-	-

  Table adapted from the detection of desmoglein isoforms in mouse tissues by RT-PCR

  This expression profile indicates that Dsg1c has a highly specific function in epidermis and liver tissues, which should be considered when designing experiments targeting this protein .

• What structural features characterize Mouse Desmoglein-1-gamma and how do they relate to function?

  Mouse Desmoglein-1-gamma (Dsg1c) contains several key structural domains that are important for its function:

  • Signal sequence: A 21-residue sequence that directs the protein to the endoplasmic reticulum .

  • Prosequence: Comprises 28 residues ending in a five-residue cleavage recognition site with a consensus (R/V)R(Q/Y)KR .

  • Extracellular domains: Contains multiple EC domains with conserved calcium-binding motifs (DXNDN and A/VXDXD), although Dsg1c has some conservative substitutions within the latter motif (ATDCE) .

  • Transmembrane domain: A 25-residue transmembrane region followed by conserved intracellular anchor and intracellular cadherin segments .

  • Repeat units: Dsg1c contains four repeat units of approximately 30 residues each containing the consensus sequence (N)(V/I/Y)(X)(V/L/Y)(T/A/R)(E), compared to Dsg1 and Dsg5 which contain five repeats .

  The specific structure of Dsg1c, particularly its four repeat units (versus five in Dsg1), suggests potential functional differences in desmosomal adhesion strength or signaling capabilities.

• How do desmogleins contribute to epithelial barrier function and what methodology can be used to study this?

  Desmogleins, including Dsg1c, are critical components of desmosomes that contribute to epithelial barrier function through:

  • Mechanical stability and cohesion of cellular layers in the skin

  • Formation of barriers that protect underlying tissues from environmental factors and prevent water loss

  • Interaction with plaque proteins and intermediate filaments mediating cell-cell adhesion

  Methodological approaches to study barrier function include:

  • Gene silencing experiments: As demonstrated with DSG1, gene silencing can be used to assess the impact on epithelial integrity. Studies have shown that DSG1 gene silencing weakens esophageal epithelial integrity and induces cell separation and impaired barrier function .

  • Raft culture models: Three-dimensional raft culture models can be used to study the role of desmogleins in differentiation and morphogenesis. This approach allows observation of structural changes in epithelial organization when desmoglein expression is altered .

  • Transcriptional analysis: Comparing transcriptional changes in Dsg-deficient models with inflamed mucosa can identify downstream effects of desmoglein dysfunction. For example, DSG1 deficiency induces transcriptional changes that overlap with the transcriptome of inflamed esophageal mucosa .