Greco M A, Lorand L, Lane W S, Baden H P, Parameswaran K N, Kvedar J C
Department of Dermatology, Harvard Medical School, Massachusetts General Hospital, Boston.
J Invest Dermatol. 1995 Feb;104(2):204-10. doi: 10.1111/1523-1747.ep12612759.
In this report, the pancornulins are identified as members of the spr (small, proline-rich) multigene family by amino acid sequence and mass spectrometry analyses. One of the pancornulins (14.9 kDa) is identical to the protein predicted by spr-1 clone 128. The other pancornulins (16.9 kDa and 22 kDa) are novel members of the spr family. Immunoelectron microscopy of purified cornified envelopes with a pancornulin-specific antibody established these proteins more definitively as cornified envelope precursors. In addition, two-dimensional electrophoretic analyses of keratinocyte extracts labeled enzymatically with dansylcadaverine (to identify amine acceptors) or dansylPGGQQIV (to identify amine donors) showed that both glutamine and lysine residues within the pancornulins participate in the isopeptide linkage characteristic of cornified envelope formation. These results contrasted with those obtained using involucrin, a prominent cornified envelope protein shown capable of acting only as an amine acceptor in this system. Novel partial cDNAs obtained after reverse transcription and polymerase chain reaction amplification of total messenger RNA with pancornulin-specific primers suggest that the spr multigene family may be even larger than previously described. The bifunctional reactivity of the pancornulins in cross-linking and the large number of family members identified to date suggest that the pancornulins and other spr-1-related proteins may be more important in cornified envelope formation than previously considered, perhaps functioning as "bridge" molecules during the early phases of cornified envelope assembly.
在本报告中，通过氨基酸序列分析和质谱分析，泛角质素被鉴定为富含脯氨酸的小分子（spr）多基因家族的成员。其中一种泛角质素（14.9 kDa）与spr-1克隆128预测的蛋白质相同。其他泛角质素（16.9 kDa和22 kDa）是spr家族的新成员。用泛角质素特异性抗体对纯化的角质包膜进行免疫电子显微镜检查，更明确地证实了这些蛋白质是角质包膜前体。此外，对角质形成细胞提取物进行二维电泳分析，用丹磺酰尸胺（用于鉴定胺受体）或丹磺酰PGGQQIV（用于鉴定胺供体）进行酶标记，结果表明泛角质素中的谷氨酰胺和赖氨酸残基均参与了角质包膜形成所特有的异肽键连接。这些结果与使用内披蛋白（一种突出的角质包膜蛋白，在该系统中仅能作为胺受体）所获得的结果形成对比。用泛角质素特异性引物对总信使RNA进行逆转录和聚合酶链反应扩增后获得的新的部分cDNA表明，spr多基因家族可能比先前描述的更大。泛角质素在交联中的双功能反应性以及迄今为止鉴定出的大量家族成员表明，泛角质素和其他与spr-1相关的蛋白质在角质包膜形成中可能比先前认为的更为重要，也许在角质包膜组装的早期阶段起着“桥梁”分子的作用。
