Nuclear Lamin Proteins

It is composed of intermediate filaments and membrane associated proteins.

Nuclear lamin proteins. General notes lamin b1 and lamin b antibodies are extremely useful as nuclear loading controls for use with nuclear extracts. The nuclear lamina is a proteinaceous structure located underneath the inner nuclear membrane inm where it associates with the peripheral chromatin. When using lamin b1 antibodies as nuclear loading controls be aware that in apoptotic cells lamin b1 is cleaved kottke tj et al. Defects in lamins or emerin cause a significance.

Nuclear lamin a c and emerin are important components of the inner nuclear membrane inm that link with chromatin and participate in the spatial organization of chromosomes and gene transcription 14 15. Nuclear lamins interact with inner nuclear membrane proteins to form the nuclear lamina on the interior of the nuclear envelope. Lamins also known as nuclear lamins are fibrous proteins in type v intermediate filaments providing structural function and transcriptional regulation in the cell nucleus. The principal proteins of the nuclear lamina are lamin a lamin b1 lamin b2 and lamin c.

The nuclear lamina is a dense 30 to 100 nm thick fibrillar network inside the nucleus of most cells. The nuclear lamina is a structure near the inner nuclear membrane and the peripheral chromatin. Prelamin a the precursor to mature lamin a lamin b1 and lamin b2 contain a carboxyl terminal caax motif that triggers farnesylation and methylation of a carboxyl terminal cysteine. During mitosis the lamina matrix is reversibly disassembled as the lamin proteins are phosphorylated.

It contains lamins and lamin associated proteins including many integral proteins of the inm chromatin modifying proteins transcriptional repressors and structural proteins. It is composed of lamins which are also present in the nuclear interior and lamin associated proteins. Lamins are nuclear structural proteins that provide critical barriers against genome instability in the nuclear envelope through dna repair dna replication transcription control and chromatin organization 138 142. Lamin b1 will also be removed from a nuclear prep if the nuclear membranes are spun out.

The nuclear envelope is composed of an outer membrane an inner membrane nuclear pore complexes and the lamina. The lamin family of proteins make up the matrix and are highly conserved in evolution. The nuclear lamina consists of a two dimensional matrix of proteins located next to the inner nuclear membrane. Recent studies suggest that a type lamins may facilitate connections between the nucleus and the cytoskeleton mediated by nuclear envelope nesprin and sun proteins.