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Table 1 The basic characteristics of the lamins

From: Chromatin states and nuclear organization in development — a view from the nuclear lamina

Lamin type Genes (in mammalsa) Major isoforms/(minor isoforms) Processing of the C-terminus Isoelectric point (pK) and solubility in mitosis Expression
A-type lamin LMNA Lamin A Lamin A and AΔ10 have a CaaX motif that is farnesylated and ultimately cleaved with an additional 15 residues from the C-terminus pK neutral Lamins A and C are expressed in most somatic differentiated cells Lamin C2 is expressed in germ cells
Lamin C Lamin C and C2 have no CaaX motif Soluble during mitosis
(Lamin AΔ10 Lamin C2)
B-type lamin LMNB1 Lamin B1 B-type lamins have a CaaX motif that is farnesylated and carboxymethylated on the cysteine, whereas the (aaX) part of the motif is removed pK acidic Lamins B1 and B2 are expressed in most or all somatic cells, but lamin B1 is notably absent from muscle cells. Lamin B3 is found in germ cells
LMNB2 Lamin B2 The farnesyl group is essential but not sufficient for the peripheral localization of B-type lamins Membrane-bound in mitosis
(Lamin B3)
  1. aThe worm Caenorhabditis elegans has a single lamin gene (lmn-1) encoding a protein that has features of both A-type and B-type lamins