半糖粒是细胞与细胞外基质之间的黏附结构。它们在将中间纤维锚定在细胞外基膜上发挥作用。在结构上，半脂质体有两种形式:I型和II型。I型半脂质体发育于分层上皮，如表皮。其主要成分包括细胞内连接蛋白果胶和BPAG1，粘附受体整合素α6β4和胶原型BP180/XVII。II型半脂质体作为I型半脂质体的简化形式出现在血管、雪旺细胞和消化道上皮中，仅由果胶和整合素α6β4组成。半糖体粘附受体通常与基底膜上的层粘连蛋白5相关。此外，层粘连蛋白5(其中层粘连蛋白2是一个亚基)通过VII型胶原蛋白与真皮层中的胶原纤维相连。半脂糖体相关蛋白的遗传缺失导致各种形式的大疱性表皮松解症，突出了它们在促进表皮和基底膜之间粘附的重要性。
层粘连蛋白γ 2链与γ 1链高度同源;但缺乏VI结构域，V、IV、III结构域较短。它在几种胎儿组织中表达，但与γ 1不同，并特异性定位于皮肤、肺和肾脏的上皮细胞。gamma 2链与alpha 3和beta 3链一起构成层粘连蛋白5(早期称为加里宁)，它是连接上皮细胞和基底膜的锚定丝的组成部分。γ 2链的上皮特异性表达暗示其作为上皮附着分子的作用，该基因的突变与交界性大疱性表皮松解症有关，这是一种因表皮-真皮连接处破坏而产生水泡的皮肤病。
Application: IP, IF, WB, IHC(f)
Clonality: Monoclonal
Host: Mouse
Purification: Supernatant
Reactivity: Bovine, Human
Hemidesmosomes are adhesive structures between cells and the extracellular matrix. They play a role in anchoring intermediate fibers to the extracellular basement membrane. Structurally, hemidesmosomes occur in two forms: Type I and Type II. Type I hemidesmosomes develop in stratified epithelia such as the epidermis. Its main components include the intracellular linker proteins Plectin and BPAG1, the adhesion receptor integrin α6β4 and collagen type BP180/XVII. Type II hemidesmosomes occur in blood vessels, Schwann cells, and digestive tract epithelia as a simplified form of Type I hemidesmosomes, consisting only plectin and integrin α6β4. The hemidesmosomal adhesion receptor is normally associated with Laminin 5 in the basement membrane. Furthermore, Laminin 5 (of which Laminin gamma 2 is a subunit) is linked to collagen fibers in the dermis via type VII collagen. Genetic deletion of hemidesmosome-related proteins causes various forms of epidermolysis bullosa, highlighting their importance in promoting adhesion between the epidermis and the basement membrane.
The Laminin gamma 2 chain is highly homologous to the gamma 1 chain; however, it lacks domain VI, and domains V, IV and III are shorter. It is expressed in several fetal tissues but differently from gamma 1, and is specifically localized to epithelial cells in skin, lung and kidney. The gamma 2 chain together with alpha 3 and beta 3 chains constitute laminin 5 (earlier known as kalinin), which is an integral part of the anchoring filaments that connect epithelial cells to the underlying basement membrane. The epithelium-specific expression of the gamma 2 chain implied its role as an epithelium attachment molecule, and mutations in this gene have been associated with junctional epidermolysis bullosa, a skin disease characterized by blisters due to disruption of the epidermal-dermal junction.