Epidermis proteins

Yochem, J., Tuck, S., Greenwald, I. and Han, M. (1999) A gp330/megalin-related protein is required in the major epidermis of Caenorhabditis elegans for completion of molting. Development 126, 597-606. 

Fig. 6 TEM micrographs of seed coat and aleurone cells of radish control seed 18 h after sowing in water e, epidermis pi, pigment layer al, aleurone layer. (A) Bar = 30 pm Particulars of the aleurone cell showing some organelles nucleus (n), plasmodesmata (pd), protein bodies (pb) and lipid droplets (Id). (B, C). Bar = 5 mm. 

It is possible to identify various factors that confer on chemicals the ability to induce skin sensitization and allergic contact dermatitis. These include the capacity to gain access to the viable epidermis across the stratum corneum, to associate stably with host proteins, to provoke a certain degree of proinflammatory cytokine production by skin cells, and to be recognized by specific T lymphocytes. The effectiveness with which these requirements are met, and possibly other properties of the chemical that influence the vigor of induced immune responses, together with the extent of exposure, will dictate the degree to which sensitization is achieved. 

Two alkaline CDases were purified from Guinea pig skin epidermis. These two enzymes were membrane bound, and their estimated molecular masses on SDS-PAGE were 60 and 148 kDa, respectively (Yada et al, 1995). No other studies followed on these two proteins. 

The posttranslationally modified cross-link S -[(Z)-2-aminovinyl]-D-cysteine (AviCys Figure 1) has been found at the C-terminus of the lantibiotics epidermin, gallidermin, cypemycin, and mutacin III. A group of decarboxylases, called LanD proteins, are encoded in the lantibiotic gene clusters and are responsible for this modification. The first LanD protein characterized was EpiD from the epidermin-producing strain S. epidermis EpiA and EpiD were separately overexpressed in E. coliand purified. 

Much of the FLS biochemical and structure/fimction analysis has focused on a protein from C. unshiu (mandarin). A cDNA was isolated based on sequence homology to an Arabidopsis FLS EST (153O10T7) and used as a probe to determine regulation of gene expression [92]. Higher expression was observed in young leaf, flower, peel, and juice sac/segment epidermis tissues. Expression decreased with tissue age, as has been observed for citrus CHS, CHI, and F3H [57]. Southern analysis... 

Reddig PJ, Dreckschmidt NE, Ahrens H, Simsiman R, Tseng C-P, Zou J, Oberley TD, Verma AK (1999) Transgenic mice overexpressing protein kinase C 8 in the epidermis are resistant to sldn tumor promotion by 12-0-tetradecanoylphorbol-13-acetat, Cancer Res 49 5710-5718... 

Rennecke J, Rehberger PA, Filrstenberger G., Johannes FJ, Stohr M, Marks F, Richter KH (1999) Protein-kinase-Cp expression correlates with enhanced kerationcate proliferation in normal and neoplastic mouse epidermis and in cell culture. Int J Cancer 80 98-103... 

Schlatterer K, Krauter G, Schlatterer B, Hecker E, Chandra P (1999) A novel protein (plO) induced by 12-0-tetradecanoyl-phorbol-13-acetate (TPA) and other hy-perplasiogenic tumor-promoting and non-promoting agents in murine epidermis. Anticancer Res 19 397-404... 

The dermis provides a base for the epidermis and contains fibroblasts that elaborate proteins, such as collagens and elastin, which are crucial for the skin s structural integrity. In addition, mast cells, enriched in a variety of proinflammatory substances, play an important role in tissue remodeling, wound healing, and fibrosis. 

Drugs that are used to treat hyperkeratosis, a thickening of the stratum corneum, are called keratolytics. Examples of these agents are salicylic acid, urea, lactic acid, and colloidal or precipitated sulfur. The precise mechanisms by which these agents treat hyperkeratosis are not known. Presumably, a common property is the ability to denature keratin, the major structural protein of the epidermis. Other beneficial effects vary among the different drugs. All of them have antimicrobial or... 

The most superficial layer of skin is the stratum comeum (SC), which consists of terminally differentiated keratinocytes (comeocytes) that originate from actively proliferating keratinocytes in lower epidermis (basale, spinosum, and granulosum cells), and contain a lamellar lipid layer secreted from lamellar bodies (Fig. 7a). Flydration of the SC is an important determinant of skin appearance and physical properties, and depends on a number of factors including the external humidity, and its structure, lipid/protein composition, barrier properties, and concentration of water-retaining osmolytes (natural moisturizing factors, NMFs) including free amino acids, ions, and other small solutes. 

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