Lamin B Function

B type lamins are encoded by lmnb1 lamin b1 and lmnb2 lamin b2 and b3 burke stewart 2013.

Lamin b function. Other studies that have investigated the structural similarities and differences between a and b type lamins have found that the positions of introns exons in b type lamins have been conserved in a type lamins with more variations in the a type lamins. One region of the protein called the sterol reductase domain gives the protein sterol reductase function specifically δ14 sterol reductase function. The severity of the disease depends on the nature of the specific mutation and whether one or both copies of the gene are affected. Lamin a and c are cleaved by caspases into large 41 50 kda and small 28 kda fragments which can be used as markers for apoptosis 4 5.

A and b type lamins regulate nuclear structure function and plasticity in cells dechat et al 2010. Different regions domains of this protein give it two distinct functions. The nuclear lamina is a filamentous structure composed of lamins that supports the inner nuclear membrane. Lamin structure and assembly.

Results from various studies suggest that lamins may have major functions in dna. The lbr gene provides instructions for making a protein called the lamin b receptor. A type lamins are encoded by a single gene lmna. Lamin b1 is also cleaved by caspases during apoptosis 9.

Vertebrate lamins consist of two types a and b. Type b lamins consist of lamin b1 and b2 encoded by separate genes 6 8. The lamins are type v intermediate filaments which can be categorized as either a type lamin a c or b type lamin b 1 b 2 according to homology of their dna sequences biochemical properties and cellular localization during the cell cycle. Several integral membrane proteins including lbr lamin b receptor lap lamin associated polypeptide 1 and lap 2 bind nuclear lamins in vitro and may influence lamin function and dynamics in vivo.

This suggests that the common ancestor of these lamin types was a b type lamin. Furukawa et al 1994. Lamins are grouped into a type and b type lamins. Lamin a and b1 expression is upregulated during heat shock.

Lamin b receptor or lbr for short is found at the envelope that surrounds. The nuclear lamina consists of two components lamins and nuclear lamin associated membrane proteins. Machiels et al 1996 a type lamins are absent in early embryonic cells but are present in. Lamin b along with heterochromatin is anchored to the inner surface of the nuclear membrane by the lamin b receptor.

Shimi et al 2008. In humans mutations in the gene that encodes a protein called lamin b receptor can lead to diseases ranging from harmless anomalies of blood cells to fatal developmental defects. In mammals alternative splicing gives rise to lamin a and lamin c and the less abundant isoforms lamin aδ10 and lamin c2 fisher et al 1986. Zastrow et al 2004 notwithstanding the role of lamin b as a heat shock responsive protein dynlacht et al 1999 the role and response of nuclear lamins upon.

The ratios of a and b type lamins important for nuclear stiffness and mechanical stability are tightly regulated in different cell types and tissues swift et al 2013. Wilson and foisner 2010.