Androgen regulation of MAK mRNAs in mouse kidney.

L D Snider,D King,J B Lingrel

doi:10.1016/s0021-9258(17)39319-5

Abstract

Androgen-regulated changes in the abundance of two mRNAs in mouse kidney have been studied with the aid of a cDNA clone. The clone was isolated from a library prepared using poly(A+) RNA from kidneys of androgen-induced mice and is designated MAK-I. Unique DNA sequence from MAK-I hybridizes to multiple RNAs which are approximately 1600 and 2200 nucleotides long, and Southern blot analysis of genomic DNA suggests that there is a single gene from which the RNAs are transcribed. When the MAK RNAs are isolated by hybrid selection and translated in a cell-free system, one polypeptide of 42,000 daltons is obtained. The transcripts, in combination, comprise approximately 0.2% of poly(A+) RNA in the kidneys of male mice. Following treatment with testosterone, this level increases 3-fold. The uninduced level of MAK mRNA in female kidneys is half of that exhibited by males and is increased 8-fold by testosterone. The mRNAs are also present and their abundance is hormonally controlled in the liver. Levels of MAK RNA detected in submaxillary gland, heart, brain, muscle, and testes are unaffected by testosterone treatment. Differences in the relative amounts of the different sized mRNAs are observed for several tissues. In addition, brain and muscle contain an intermediate sized mRNA instead of the smaller one seen in other tissues. Functional androgen receptor is required for expression of MAK RNA in kidney as shown by reduced levels in Tfm mice. Hormones produced by or controlled by the pituitary gland do not appear to be involved in the regulation of MAK RNA levels.

Highlights

Androgen-regulated changes in the abundaonfctewo complex with specific DNA sequences in and near induced mRNAs in mouse kidney have been studied with the genes [9,10,11,12,13] has been reported
Twoandrogenstimulated genes, a2,globulin which is expressed in liver [14] and prostatic binding protein C3gene [15], have been transformedintocultured cells, and the latter is responsive to free system, one polypeptide of 42,000 daltons is ob- androgens i n vitro
We have examined the protein product of the expression is modulatedis thought toinvolve increased tran- mRNA by i n vitro translation and the gene from which it is scription asa result of high affinity binding of the hormone- transcribed by Southern blot analysisof genomic DNA

Summary

Androgen Regulation of MAK mRNAs in Mouse Kidney*

From the Departmentof Microbiologyand Molecular Genetics, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267. The clone was isolated from a The molecular mechanisms by whichandrogens affect gene library prepared usingpoly(A+)RNA from kidneys of expression, are not as well characterized as other androgen-induced mice and is designated MAK-I. We have examined the protein product of the expression is modulatedis thought toinvolve increased tran- mRNA by i n vitro translation and the gene from which it is scription asa result of high affinity binding of the hormone- transcribed by Southern blot analysisof genomic DNA. An equal volume of the following buffer was added, and the resulting were hybridized for 4 h a t 50 "C with 100 pg of polyadenylated RNA mixture was incubated on ice for 20 min: 50 mM Tris, pH 8.0, 62.5 isolated from induced or uninduced female mouse kidney. Homogenized in guanidinehydrochloride solution [34] usinga Brinkmann Polytron.Following centrifugation of the homogenatea t 12,000 X g for 10 min a t 10 "C, the supernatantwas collected and acidified

RESULTS

Induction hours

Variations in the relative levels of abundance of multiple

DISCUSSION

Examination of the time course of deinduction indicates