Partitioning defective 6 homolog alpha (PARD6A)

Partitioning defective 6 homolog alpha (PARD6A) is a scaffolding protein belonging to the Par6 family, involved in the regulation of cell polarity, asymmetric cell division, and epithelial tight junctions in humans[1][4][5][8]. PARD6A contains a PDZ domain and a semi-CRIB domain (semi-Cdc42/Rac interactive binding), allowing it to form complexes with key polarity and signaling proteins including Par3, atypical protein kinase C (aPKC), and small GTPases such as Cdc42 and Rac1[1][2][3][5]. As part of the Par complex, PARD6A orchestrates the formation and maintenance of cell polarity, centrosome integrity, and tight junctions, making it essential in developmental patterning, tissue organization, and cellular homeostasis[4][5][6]. Dysregulation or overexpression of PARD6A contributes to pathological processes, notably the epithelial-mesenchymal transition (EMT), which is significant in cancer invasion and metastasis (e.g., breast and ovarian cancer)[2][3][7]. Experimental data demonstrates that PARD6A is overexpressed in several cancers, where it enhances migratory, invasive, and proliferative capacities through signaling axes such as the integrin β1–ILK–SNAIL1 pathway[7]. PARD6A is not currently considered a direct therapeutic target or biomarker in clinical use, and no drugs are known to interact specifically with it. However, its central role in cell polarity and tumor progression makes it of substantial interest for further research in oncology and developmental biology.

Other names

Par-6 family cell polarity regulator alphaPAR6APAR-6APar6αTip-40TAX40Partitioning-defective protein 6 alphaTax-interacting protein 40Par-6 alphaPAR6alphaPar6C