|PDCD4 in Human Stomach. PDCD4 was detected in immersion fixed paraffin-embedded sections of human stomach using Sheep Anti-Human PDCD4 Antigen Affinity-purified Polyclonal Antibody (Catalog # AF7019) at 3 µg/mL overnight at 4 °C. Tissue was stained using the Anti-Sheep HRP-DAB Cell & Tissue Staining Kit (brown; Catalog # CTS019) and counterstained with hematoxylin (blue). Specific staining was localized to nuclei in epithelial cells. View our protocol for Chromogenic IHC Staining of Paraffin-embedded Tissue Sections.|
|PDCD4 in MCF-7 Human Cell Line. PDCD4 was detected in immersion fixed MCF‑7 human breast cancer cell line using Sheep Anti-Human PDCD4 Antigen Affinity-purified Polyclonal Antibody (Catalog # AF7019) at 1.7 µg/mL for 3 hours at room temperature. Cells were stained using the NorthernLights™ 557-conjugated Anti-Sheep IgG Secondary Antibody (yellow, upper panel; Catalog # NL010) and counterstained with DAPI (blue, lower panel). Specific staining was localized to nuclei. View our protocol for Fluorescent ICC Staining of Cells on Coverslips.|
PDCD4 (Programmed cell death protein 4; also H731) is a 54-64 kDa member of the PDCD4 family of molecules. It is widely expressed, being found in mammary epithelium, CD34+ bone marrow progenitor cells, fibroblasts and keratinocytes. PDCD4 is both cytoplasmic and nuclear. In the cytoplasm, it blocks protein translation by binding to eIF4A, an act that dissociates eIF4G and mRNA from eIF4A. In the nucleus, it seems to block transcription of select genes, one of which is MAP4K1, a key enzyme in the AP-1-mediated transcription pathway. Human PDCD4 is 469 amino acids (aa) in length. It contains an NLS (aa 58-64), an MI domain (aa 163-284), another NLS (aa 241-250) and a second MI domain (aa 326-449). There are at least seven utilized Ser/Thr phosphorylation sites and one Tyr phosphorylation site. There are two potential splice forms, one that contains a deletion of aa 15-28, and a second that may show a three aa substitution for aa 2-15. Over aa 212-357, human PDCD4 shares 98% aa identity with mouse PDCD4.