REGULATION OF TYPE-I (EPIDERMAL) TRANSGLUTAMINASE MESSENGER-RNA LEVELS DURING SQUAMOUS DIFFERENTIATION - DOWN REGULATION BY RETINOIDS
REGULATION OF TYPE-I (EPIDERMAL) TRANSGLUTAMINASE MESSENGER-RNA LEVELS DURING SQUAMOUS DIFFERENTIATION - DOWN REGULATION BY RETINOIDS
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DOI：
10.1128/mcb.9.11.4846
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发表时间：
1989-11-01
影响因子：
5.3
通讯作者：
JETTEN, AM
中科院分区：
文献类型：
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作者：
FLOYD, EE;JETTEN, AM
兔气管上皮细胞的鳞状分化伴随着I型（表皮）转谷氨酰胺酶活性的约50倍增加，而II型（组织）转谷氨酰胺酶的水平几乎无法检测到。为了鉴定编码I型转氨酶的cDNA，我们筛选了从鳞状分化的兔气管上皮细胞分离的poly（A）+ RNA制备的cDNA克隆文库。鉴定了跨越2.8个酶的范围的四个重叠克隆（由克隆pTG-7表示）; pTG-7的部分测序表明其编码类似于转氨酶的蛋白。pTG-7与不同于II型转氨酶的3.6-转氨酶mRNA杂交。pTG-7 mRNA水平在增殖细胞中较低，在鳞状分化细胞中显著增加，并且可以通过细胞在高浓度（2 mM）的钙离子中生长而进一步增强。阻断鳞状表型表达的视黄酸阻止了pTG-7 mRNA水平的增加。pTG-7 mRNA水平的这些变化与在类似培养条件下观察到的I型转氨酶活性的变化平行。这些数据表明，pTG-7编码I型转氨酶的mRNA，该mRNA的表达受视黄酸负调控。
Squamous differentiation of rabbit tracheal epithelial cells is accompanied by an approximately 50-fold increase in the activity of type I (epidermal) transglutaminase, while the levels of type II (tissue) transglutaminase remain almost undetectable. To identify a cDNA encoding type I transglutaminase, we screened a library of cDNA clones prepared from poly(A)+ RNA isolated from squamous-differentiated rabbit tracheal epithelial cells. Four overlapping clones (represented by clone pTG-7) which span a range of 2.8 kilobases were identified; partial sequencing of pTG-7 indicated that it encodes a transglutaminaselike protein. pTG-7 hybridized to a 3.6-kilobase mRNA which is distinct from that for type II transglutaminase. pTG-7 mRNA levels were low in proliferative cells, increased dramatically in squamous-differentiated cells, and could be further enhanced by growth of the cells in high concentrations (2 mM) of calcium ions. Retinoic acid, which blocks the expression of the squamous phenotype, prevented this increase in pTG-7 mRNA levles. These changes in levels of pTG-7 mRNA parallel the changes in type I transglutaminase activity observed under similar culture conditions. These data indicate that pTG-7 encodes the mRNA for tansglutaminase type I and that expression of this mRNA is negatively regulated by retinoic acid.