Antibodies to Lamins - FocusOn 028

Antibody tools for the detection of lamins

Acris Antibodies offers a full panel of antibodies to lamin A, B and C. These antibodies are suitable for various applications like immunohistochemistry, immunofluorescence or western blotting.

Introduction

Lamins are intermediate filament-type proteins which form major components of the nuclear lamina. Lamins form dimers through their rod domain and interact with chromatin and integral proteins of the inner nuclear membrane through binding sites located in their carboxy-terminal globular tail. Mammals have two main type lamins, A and B.

B-type lamins

B-type lamins B1 and B2 are encoded by two distinct genes, LMNB1 and LMNB2 (Höger et al. 1990). Lamin B3 is a germ cell specific protein generated by differential splicing and alternative polyadenylation of the LMNB2 gene (Furukawa et al. 1993). B-type lamins undergo a series of modifications, such as farnesylation and phosphorylation. Increased phosphorylation of the lamins occurs before envelope disintegration and probably plays a role in regulating lamin associations.

Fig. 1: Immunostaining of human epidermis with: a) lamin A antibody Cat.-No. BM4500; b) lamin B1 antibody Cat.-No. BM4501; c) lamin B2 antibody Cat.-No. BM4502

Fig. 2: One-dimensional immunoblotting of lamin antibodies. Lysates of a cell line were immunoprecipitated with the lamin B1 antibody clone 119D5F1 Cat.-No. BM4501 (panel A), the lamin B2 antibody clone LN43 Cat.-No. BM4502 (panel B) and the lamin A antibody clone 133A2 Cat.-No. BM4500 (panel C). The immunoprecipitated heavy and light chains of immunoglobulins recognized by the secondary antibody are indicated by h and l, respectively

A-type lamins

A-type lamins A and C are derived by differential splicing and alternative poly-adenylation from one gene, the LMNA gene. Mutations in LMNA have been shown to cause a whole range of human disorders, including autosomal dominant and recessive forms of Emery-Dreifuss muscular dystrophy (EDMD2/3), Limb-Girdle muscular dystrophy (LGMD1B), dilated cardiomyopathy (conduction-system disease, CMD1A), familial autosomal domi-nant partial lipodystrophy (Dunnigan variety, FPLD), autosomal recessive Charcot-Marie-Tooth disease (CMT2B1), mandibuloacral dysplasia (MAD), Hutchinson-Gilford progeria syndrome (HGPS), lipoatrophy with diabetes, hepatic steatosis, hypertrophic cardiomyopathy and leukomelanodermic papules (LDHPC), Werner syndrome (WRN) and cardiocutaneous progeria syndrome (CCPS).

Lamin A is a 664 amino acid protein with a molecular weight of 70 kDa (calculated 74,139 Da) and a pI of 7.0 (theoretical pI 7.4). Lamin A consists of a central rod domain flanked by hydrophobic N- and C-terminal domains. After farnesylation at the CAAX-box motif, the 18 most C-terminal amino acids of lamin A are removed by proteolytic cleavage to generate the mature lamin A protein (Hennekes et al. 1994).

Lamin C (572 amino acids) differs from lamin A after amino acid 566, containing an alternative 6 amino acid C-terminal end (VSGSRR).

Fig. 3: Staining with lamin A/C antibody clone JOL2 Cat.-No. AM01387SU-S: 3a) Immunofluorescence staining of human dermal fibroblasts using lamin A/C and Ki67, 3b) Immunohistochemistry of formalin-fixed, paraffin-embedded (FFPE) human tonsil, 3c) Immunohistochemistry of human skin (FFPE)

Fig. 4: Western blot using lamin A/C clone JOL5 Cat.-No. BM4505S showing extracts from mouse myoblasts c2c12 (upper band is lamin A, lower band is lamin C)	Fig. 5: Western blot analysis of lamin A/C in lysates from Jurkat cells (lane 1 and 2), mouse small intestine (lane 3) and rat kidney (lane 4) using polyclonal lamin A/C antibody Cat.-No. AP00082PU-N
Fig. 6: Immunofluorescence staining of lamin A/C in HeLa cells using Cat.-No. SM5157	Fig. 7: Western blot of lamin A/C from HeLa cell extract using Cat.-No. SM5157
Fig. 8: Immunohistochemistry: Lamin B2 antibody Cat.-No. AP19033PU-N staining of paraffin-embedded Cal27 xenograft at 1/100 dilution	Fig. 9: Western Blot: Lamin B2 antibody Cat.-No. AP19033PU-N staining of H1299 (A), Hela (B), HepG2 (C) whole cell lysates

References

Höger TH et al.
Characterization of a second highly conserved B-type lamin present in cells previously thought to contain only a single B-type lamin. Chromosoma, Oct 1990; 99(6): 379-90. [PMID 2102682 ]

Furukawa K et al.
cDNA cloning of a germ cell specific lamin B3 from mouse spermatocytes and analysis of its function by ectopic expression in somatic cells. EMBO J, Jan 1993; 12(1): 97-106. [PMID 8094052 ]

Hennekes E et al.
The role of isoprenylation in membrane attachment of nuclear lamins. A single point mutation prevents proteolytic cleavage of the lamin A precursor and confers membrane binding properties. J Cell Sci, Apr 1994; 107 (Pt 4): 1019-29. [PMID 8056827 ]

Further readings

See the PDF-version: FocusOn 028