Localization of KANK2 to Focal or Fibrillar Adhesions Influences Migration in Melanoma Cell Lines

Integrins form focal adhesions (FAs) at the cell edge and fibrillar adhesions (FBs) located centrally, with both serving as a link to the actin cytoskeleton. Talins 1 and 2, key mechanosensitive proteins, are not functionally redundant. Talin1 is essential to FAs, while talin2 is found in large FAs and FBs. KANK (kidney ankyrin repeat-containing) family proteins regulate adhesion dynamics, with KANK2 binding both talins in FAs and localizing to FBs where only talin2 is present. Previously, we showed in melanoma cell line MDA-MB-435S that talin2 within integrin αVβ5 FAs interacts with KANK2 to regulate actin-microtubule (MT) dynamics, and knocking down either protein reduces cell migration. Here, we demonstrate that RPMI-7951 melanoma cells also use integrin αVβ5 FAs for adhesion but additionally form integrin α5β1 FBs, and that KANK2 and talin2 are present in both structures. KANK2 functionally interacts with talin1 to maintain FAs, and with talin2 to regulate their dynamics. KANK2 within FBs regulates cell migration. This was demonstrated upon KANK2 knockdown that mirrors integrin α5 knockdown, increasing migration via MTs. Overall, our study highlights the distinct roles of KANK2 and talin2 in different adhesion structures, influencing melanoma cell migration.