FUNCTION : LAMINS ARE COMPONENTS OF THE NUCLEAR LAMINA, A FIBROUS LAYER ON THE NUCLEOPLASMIC SIDE OF THE INNER NUCLEAR MEMBRANE, WHICH IS THOUGHT TO PROVIDE A FRAMEWORK FOR THE NUCLEAR ENVELOPE AND MAY ALSO INTERACT WITH CHROMATIN. LAMIN A AND C ARE PRESENT IN EQUAL AMOUNTS IN THE LAMINA OF MAMMALS. SUBUNIT : HOMODIMER OF LAMIN A AND LAMIN C. INTERACTS WITH LAMIN-ASSOCIATED POLYPEPTIDES IA AND IB AND WITH EMERIN. SUBCELLULAR LOCATION : Nuclear. ALTERNATIVE PRODUCTS : 3 isoforms; Lamin A (shown here), Lamin C and ADelta10/Lamin ADelta10; are produced by alternative splicing. PTM : INCREASED PHOSPHORYLATION OF THE LAMINS OCCURS BEFORE ENVELOPE DISINTEGRATION AND PROBABLY PLAYS A ROLE IN REGULATING LAMIN ASSOCIATIONS. DISEASE : DEFECTS IN LMNA ARE A CAUSE OF EMERY-DREIFUSS MUSCULAR DYSTROPHY (EDMD), AN AUTOSOMAL RECESSIVE OR DOMINANT DISEASE CHARACTERIZED BY CARDIOMYOPATHY WITH CONDUCTION DEFECTS. DISEASE : DEFECTS IN LMNA ARE A CAUSE OF DILATED CARDIOMYOPATHY 1A (CMD1A). DISEASE : DEFECTS IN LMNA ARE A CAUSE OF FAMILIAL PARTIAL LIPODYSTROPHY (DUNNIGAN VARIETY) (FPLD), AN AUTOSOMAL DOMINANT DISORDER CHARACTERIZED BY MARKED LOSS OF SUBCUTANEOUS ADIPOSE TISSUE FROM THE EXTREMITIES AND TRUNK BUT BY EXCESS FAT DEPOSITION IN THE HEAD AND NECK. FREQUENTLY ASSOCIATED WITH PROFOUND INSULIN RESISTANCE, DYSLIPIDEMIA, AND DIABETES. MISCELLANEOUS : THERE ARE THREE TYPES OF LAMINS IN HUMAN CELLS: A, B, AND C. MISCELLANEOUS : THE STRUCTURAL INTEGRITY OF THE LAMINA IS STRICTLY CONTROLLED BY THE CELL CYCLE, AS SEEN BY THE DISINTEGRATION AND FORMATION OF THE NUCLEAR ENVELOPE IN PROPHASE AND TELOPHASE, RESPECTIVELY. SIMILARITY : BELONGS TO THE INTERMEDIATE FILAMENT FAMILY. CAUTION : Ref.1 (CAA27173) sequence differs from that shown due to a frameshift in position 582. |
|
25-JAN-03
Last Update 13-Mar-03