Open AccessThe cDNA structure and expression analysis of the genes for the cysteine proteinase inhibitor cystatin C and for β 2 ‐microglobulin in rat brain
Author(s) -
COLE Timothy,
DICKSON Phillip W.,
ESNARD Frederic,
AVERILL Sharon,
RISBRIDGER Gail P.,
GAUTHIER Francis,
SCHREIBER Gerhard
Publication year - 1989
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1989.tb15174.x
Subject(s) - choroid plexus , microbiology and biotechnology , complementary dna , biology , beta 2 microglobulin , northern blot , messenger rna , cdna library , in situ hybridization , cystatin , gene expression , cystatin c , gene , biochemistry , endocrinology , central nervous system , renal function , immunology
Tissue patterns of gene expression were analyzed by measuring mRNA levels and incorporation of radioactive amino acids for cystatin C and β 2 ‐microglobulin, the two extracellular proteins in the brain with the highest ratio of concentration in cerebrospinal fluid over that in blood plasma. The primary structure of rat cystatin C mRNA from choroid plexus was determined by nucleotide sequencing of cloned cDNA and the tissue patterns of gene expression were analysed by RNA blot analysis and in situ hybridization. Cystatin C was found to be composed of 120 amino acids and to contain a potential site for N‐linked glycosylation. The tissue with the highest cystatin C mRNA level was the choroid plexus of the brain. Cystatin C mRNA was also detected in lower levels in other areas of the brain, testis, epididymis, seminal vesicles, prostate, ovary, submandibular gland, and, in trace amounts, in liver. Choroid plexus pieces in culture secreted radioactive cystatin C when incubated with radioactive leucine. Rat β 2 ‐microglobulin cDNA was cloned and identified by nucleotide sequencing and comparison of the obtained sequence with that of mouse and human β 2 ‐microglobulin cDNA. Tissue levels of β 2 ‐microglobulin mRNA in the rat were measured by hybridization to rat β 2 ‐microglobulin cDNA. The highest levels of β 2 ‐microglobulin mRNA were observed in liver and choroid plexus. Other parts of the brain and testis contained lower levels of β 2 ‐microglobulin mRNA.