Nuclear A Type Lamin

The nuclear envelope is composed of an outer membrane an inner membrane nuclear pore complexes and the lamina.

Nuclear a type lamin. Remarkably over 400 distinct point mutations have been so far identifie. 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. Lamin a and lamin c alternatively spliced products of lmna are key structural components of the nuclear lamina an intermediate filament meshwork lying beneath the inner nuclear membrane. Both lamin a and lamin c contain an aminoterminal globular domain a central helical rod domain and a carboxyterminal globular domain 2 4.

The farnesylation of prelamin a was assumed to be important for the targeting of mature lamin a to the inner nuclear membrane. The a and b type lamins collectively comprise lamina. Nuclear lamins interact with inner nuclear membrane proteins to form the nuclear lamina on the interior of the nuclear envelope. Lamins are present in all animals but are not found in microorganisms.

In mammals a type lamins lamin a and c are encoded by the lmna gene whereas lamin b1 and lamin b2 are transcribed from the lmnb1 and lmnb2 genes respectively. However the mature lamin a in lamin a only mice was positioned normally at the nuclear rim indistinguishable from mature lamin a in wild type mice. Expression of b type lamins was found in all the different cell lines. Nuclear a type and b type lamin expression was investigated in the major human lung cancer subtypes.

The nuclear lamina consists of two components lamins and nuclear lamin associated membrane proteins. Lamins at a glance journal of cell science. The neuronal migration abnormality is explained by a weakened nuclear lamina that interferes with nucleokinesis a nuclear translocation process requi. Twenty two human lung cancer cell lines and 46 fresh frozen human lung cancer specimens were examined.

Deficiencies in either lamin b1 or lamin b2 cause both defective migration of cortical neurons in the developing brain and reduced neuronal survival. 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. Lamin a is a component of the nuclear envelope that is synthesized as a precursor prelamin a molecule and then processed into mature lamin a through sequential steps of posttranslational modifications and proteolytic cleavages. Lamins have elastic and mechanosensitive properties and can alter gene regulation in a feedback response to mechanical cues.

Small cell lung cancer sclc squamous cell carcinomas and adenocarcinomas both non sclc. These laminopathies include emery dreifuss muscular dystrophy edmd dilated cardiomyopathy type 1a limb girdle. Lamins are intermediate filament type proteins which form major components of the nuclear lamina.