PAWS1 controls cytoskeletal dynamics and cell migration through association with the SH3 adaptor CD2AP

Abstract

Our previous studies of PAWS1 (protein associated with SMAD1; also known as FAM83G) have suggested that this molecule has roles beyond BMP signalling. To investigate these roles, we have used CRISPR/Cas9 to generate PAWS1-knockout U2OS osteosarcoma cells. Here, we show that PAWS1 plays a role in the regulation of the cytoskeletal machinery, including actin and focal adhesion dynamics, and cell migration. Confocal microscopy and live cell imaging of actin in U2OS cells indicate that PAWS1 is also involved in cytoskeletal dynamics and organization. Loss of PAWS1 causes severe defects in F-actin organization and distribution as well as in lamellipodial organization, resulting in impaired cell migration. PAWS1 interacts in a dynamic fashion with the actin/cytoskeletal regulator CD2AP at lamellae, suggesting that its association with CD2AP controls actin organization and cellular migration. Genetic ablation of CD2AP from U2OS cells instigates actin and cell migration defects reminiscent of those seen in PAWS1-knockout cells.This article has an associated First Person interview with the first authors of the paper.

FAM83G/Fam83g genetic variants affect canine and murine hair formation

“…Factors such as redundancy in cellular networks, cell microenvironment and timing can explain these distinct tissue‐dependent features. Hence, together with the recent involvement of FAM83G in actin cytoskeletal arrangements and cell migration, our observations might explain the phenotype of palmoplantar hyperkeratosis and altered hair coat in affected dogs and humans …”

Characterisation of the biochemical and cellular roles of native and pathogenic amelogenesis imperfecta mutants of FAM83H

“…Outside of the PACK1 domain, the FAM83 proteins are unique and share no sequence similarity or homology. Consistent with this, we have found that different FAM83 members have unique interacting partners and cellular roles [ [2] , [3] , [4] , [5] , [6] ]. By employing a proteomics approach, we identified FAM83G, also known as Protein Associated with SMAD1 (PAWS1), as a novel interactor of SMAD1 and a novel component of the BMP signaling pathway [ 3 ].…”

“…We have verified the interaction between FAM83D and CK1α in mitosis and demonstrated that it is necessary for correct spindle positioning in mitosis, and also confirmed the interaction between FAM83D and DYNLL1 and HMMR [ 6 ]. Similarly, we have validated the interactions of PAWS1 with CK1α [ 5 ], CD2AP [ 4 ] and SMAD1 [ 3 ] ( Fig. 2 A).…”

PAWS 1 controls Wnt signalling through association with casein kinase 1α

“…Similarly, BMP‐induced phosphorylation of SMAD1 in PAWS1 −/− U2OS cells created by CRISPR/Cas9 genome editing 19 resembles that in wild‐type U2OS cells as well as that in PAWS1 −/− cells in which PAWS1 has been restored (Fig 2C). The same is true for TGFβ‐induced phosphorylation of SMAD2/3 in the three cell lines (Fig 2C).…”