Lamin refers to a group of fibrous proteins known as nuclear lamins, which are components of type V intermediate filaments. These proteins are primarily located within the cell nucleus, where they interact with inner nuclear membrane proteins to form the nuclear lamina on the interior of the nuclear envelope.
Nuclear lamins provide essential structural functions and transcriptional regulation within the cell. They possess elastic and mechanosensitive properties that allow them to alter gene regulation in response to mechanical cues. These proteins are present in all animals but are notably absent in fungi, plants, and microorganisms.
Lamin proteins are involved in several critical cellular processes, including the disassembling and reforming of the nuclear envelope during mitosis, the positioning of nuclear pores, and programmed cell death. Mutations in lamin genes can lead to various life-threatening genetic conditions known as laminopathies.