Binding of matrix attachment regions to nuclear lamin is mediated by the rod domain and depends on the lamin polymerization state

The nuclear matrix maintains specific interactions with genomic DNA at sites known as matrix attachment regions (SARs). M/SARs bind in vitro to lamin polymers. We show that the polymerized α-helical rod domain of lamin Dm₀ provides by itself the specific binding to the ftz M/SAR. In contrast, unpolymerized rod domain does not bind specifically to this M/ SAR. Non-specific binding to DNA is also observed with Dm₀ containing a point mutation that impairs its ability to polymerize or with the isolated tail domain. These data suggests that the specific binding of lamins to M/SARs requires the rod domain and depends on the lamin polymerization state.