Lamin B1 Explained

Lamin-B1 is a protein that in humans is encoded by the LMNB1 gene.^{[1] [2] [3]}

The nuclear lamina consists of a two-dimensional matrix of proteins located next to the inner nuclear membrane. The lamin family of proteins make up the matrix and are highly conserved in evolution. During mitosis, the lamina matrix is reversibly disassembled as the lamin proteins are phosphorylated. Lamin proteins are thought to be involved in nuclear stability, chromatin structure, and gene expression. Vertebrate lamins consist of two types, A and B. This gene encodes one of the two B type proteins, B1. Lamin B, along with heterochromatin, is anchored to the inner surface of the nuclear membrane by the lamin B receptor.

Interactions

LMNB1 has been shown to interact with Thymopoietin.^{[4] [5]} When double-strand breaks are induced in DNA by ionizing radiation, lamin B1 promotes repair of the breaks, as well as cell survival, by maintaining the level of the RAD51 protein that is employed in homologous recombinational repair.^[6]

Pathology

Mutations affecting the LMNB1 gene cause autosomal dominant adult-onset demyelinating leukodystrophy.

See also

• Lamin B2

Further reading

• Gruenbaum Y, Wilson KL, Harel A, etal . Review: nuclear lamins--structural proteins with fundamental functions. . J. Struct. Biol. . 129 . 2–3 . 313–23 . 2000 . 10806082 . 10.1006/jsbi.2000.4216 .
• Worman HJ, Courvalin JC . The inner nuclear membrane . J. Membr. Biol. . 177 . 1 . 1–11 . 2000 . 10960149 . 10.1007/s002320001096 . 20121844 .
• Djabali K, Portier MM, Gros F, etal . Network antibodies identify nuclear lamin B as a physiological attachment site for peripherin intermediate filaments . Cell . 64 . 1 . 109–21 . 1991 . 1986862 . 10.1016/0092-8674(91)90213-I . 6246606 .
• Foisner R, Traub P, Wiche G . Protein kinase A- and protein kinase C-regulated interaction of plectin with lamin B and vimentin . Proc. Natl. Acad. Sci. U.S.A. . 88 . 9 . 3812–6 . 1991 . 2023931 . 10.1073/pnas.88.9.3812 . 51543 . 1991PNAS...88.3812F . free .
• Pollard KM, Chan EK, Grant BJ, etal . In vitro posttranslational modification of lamin B cloned from a human T-cell line . Mol. Cell. Biol. . 10 . 5 . 2164–75 . 1990 . 2325650 . 10.1128/mcb.10.5.2164. 360564 .
• Müller WE, Okamoto T, Reuter P, etal . Functional characterization of Tat protein from human immunodeficiency virus. Evidence that Tat links viral RNAs to nuclear matrix . J. Biol. Chem. . 265 . 7 . 3803–8 . 1990 . 10.1016/S0021-9258(19)39665-6 . 2406262 . free .
• Müller WE, Wenger R, Reuter P, etal . Association of Tat protein and viral mRNA with nuclear matrix from HIV-1-infected H9 cells . Biochim. Biophys. Acta . 1008 . 2 . 208–12 . 1989 . 2544227 . 10.1016/0167-4781(80)90011-1.
• Eldridge R, Anayiotos CP, Schlesinger S, etal . Hereditary adult-onset leukodystrophy simulating chronic progressive multiple sclerosis . N. Engl. J. Med. . 311 . 15 . 948–53 . 1984 . 6472420 . 10.1056/NEJM198410113111504 .
• Ye Q, Worman HJ . Protein-protein interactions between human nuclear lamins expressed in yeast . Exp. Cell Res. . 219 . 1 . 292–8 . 1995 . 7628545 . 10.1006/excr.1995.1230 . free .
• Goss VL, Hocevar BA, Thompson LJ, etal . Identification of nuclear beta II protein kinase C as a mitotic lamin kinase . J. Biol. Chem. . 269 . 29 . 19074–80 . 1994 . 10.1016/S0021-9258(17)32276-7 . 8034666 . free .
• Broers JL, Machiels BM, Kuijpers HJ, etal . A- and B-type lamins are differentially expressed in normal human tissues . Histochem. Cell Biol. . 107 . 6 . 505–17 . 1997 . 9243284 . 10.1007/s004180050138 . 24088247 .
• Maison C, Pyrpasopoulou A, Theodoropoulos PA, Georgatos SD . The inner nuclear membrane protein LAP1 forms a native complex with B-type lamins and partitions with spindle-associated mitotic vesicles . EMBO J. . 16 . 16 . 4839–50 . 1997 . 9305626 . 10.1093/emboj/16.16.4839 . 1170119 .
• Lin F, Worman HJ . Expression of nuclear lamins in human tissues and cancer cell lines and transcription from the promoters of the lamin A/C and B1 genes . Exp. Cell Res. . 236 . 2 . 378–84 . 1997 . 9367621 . 10.1006/excr.1997.3735 . free .
• Vodicka MA, Koepp DM, Silver PA, Emerman M . HIV-1 Vpr interacts with the nuclear transport pathway to promote macrophage infection . Genes Dev. . 12 . 2 . 175–85 . 1998 . 9436978 . 10.1101/gad.12.2.175 . 316441 .
• Furukawa K, Kondo T . Identification of the lamina-associated-polypeptide-2-binding domain of B-type lamin . Eur. J. Biochem. . 251 . 3 . 729–33 . 1998 . 9490046 . 10.1046/j.1432-1327.1998.2510729.x . free .
• Kowluru A . Evidence for the carboxyl methylation of nuclear lamin-B in the pancreatic beta cell . Biochem. Biophys. Res. Commun. . 268 . 2 . 249–54 . 2000 . 10679189 . 10.1006/bbrc.2000.2107 .

Notes and References

1. Lin F, Worman HJ . Structural organization of the human gene (LMNB1) encoding nuclear lamin B1 . Genomics . 27 . 2 . 230–6 . Nov 1995 . 7557986 . 10.1006/geno.1995.1036 . free .
2. Wydner KL, McNeil JA, Lin F, Worman HJ, Lawrence JB . Chromosomal assignment of human nuclear envelope protein genes LMNA, LMNB1, and LBR by fluorescence in situ hybridization . Genomics . 32 . 3 . 474–8 . Feb 1997 . 8838815 . 10.1006/geno.1996.0146 . free .
3. Web site: Entrez Gene: LMNB1 lamin B1.
4. Furukawa . K . Kondo T . Feb 1998 . Identification of the lamina-associated-polypeptide-2-binding domain of B-type lamin . Eur. J. Biochem. . 251 . 3 . 729–33 . GERMANY. 0014-2956. 9490046 . 10.1046/j.1432-1327.1998.2510729.x . free .
5. Foisner . R . Gerace L . Jul 1993 . Integral membrane proteins of the nuclear envelope interact with lamins and chromosomes, and binding is modulated by mitotic phosphorylation . Cell . 73 . 7 . 1267–79 . UNITED STATES. 0092-8674. 8324822 . 10.1016/0092-8674(93)90355-T . 10641633 .
6. Liu NA, Sun J, Kono K, Horikoshi Y, Ikura T, Tong X, Haraguchi T, Tashiro S. Regulation of homologous recombinational repair by lamin B1 in radiation-induced DNA damage. FASEB J. 2015 Jun;29(6):2514-25. doi: 10.1096/fj.14-265546. Epub 2015 Mar 2. PMID 25733566