Fig. 1. Regions in lamins A and C to which partners bind. The structural domains (head, rod, tail) of prelamin A are shown. Exons 1-12 encoding residues 1-664 are numbered; the last residue encoded by each exon (except exon 11) is given above. The Ig-fold domain, which includes exons 8 and 9, is shaded gray. Residues 1-566 of lamin A and lamin C are identical. Unique lamin C tail residues 567-572 are produced by alternative mRNA splicing; thus the extreme C-terminal regions of lamins A and C may have distinct binding properties. The zigzag represents the farnesyl moiety on prelamin A; the farnesylated C-terminal peptide is normally removed by proteolytic cleavage after residue 646 (bold; dotted line) to generate mature lamin A. Colored bars indicate the region(s) in lamins A and C required for each named partner to bind, as detailed in Table 1 (e.g. actin can bind two different regions in the tail). For partners with question marks, the binding region in lamin A/C is unmapped. Based on current incomplete knowledge, interactions were loosely color-coded (top to bottom) as blue (architectural), orange (chromatin), yellow (gene regulation), pink (signaling) and green (unknown). Some partners (e.g. BAF) will continue to defy categorization until more is known about their functions.