The human cystatin C gene promoter: functional analysis and identification of heterogeneous mRNA.
Human cystatin C is a low molecular weight protein involved in the control of human cysteine proteinase activity as well as microbial cysteine proteinase activity threatening the integrity of tissues. The gene for cystatin C is located on the short arm of chromosome 20, spans 6.5 kb and has three exons. To understand the mechanisms for the expression of cystatin C at the transcriptional level we mapped the 5' boundary of mRNA transcripts and studied the 5'-region of the cystatin C gene in a transient expression system with chimeric constructs utilizing various fragments of 1.1 kb of the 5'-flanking region coupled to the gene for human growth hormone. Mapping of the 5'-end of human cystatin C mRNA from placenta and seminal vesicles (low to medium versus high cystatin C expression, respectively) identified three major transcription initiation sites (positions -75, -78 and -80, A of initiation ATG as +1) and three minor sites (positions -98, -101 and -103). The relative amounts of different mRNA species were approximately the same in these two tissues. Functional analysis of the 5'-region in cultured HeLa cells revealed one region (positions -279 to -156) with a strong positive effect on transcription and comprising three identical tandemly arranged GC-rich sequences.
Olafsson
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Department of Clinical Chemistry, University Hospital, Lund, Sweden.
D001483:Base Sequence; D001665:Binding Sites; D002874:Chromosome Mapping; D055316:Cystatin C; D015891:Cystatins / Q000235:genetics*; D015853:Cysteine Proteinase Inhibitors / Q000235:genetics*; D005260:Female; D005786:Gene Expression Regulation / Q000235:genetics; D013006:Growth Hormone / Q000096:biosynthesis; D006367:HeLa Cells; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D010920:Placenta / Q000737:chemistry; D010957:Plasmids; D011247:Pregnancy; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012333:RNA, Messenger / Q000302:isolation & purification*; D012669:Seminal Vesicles / Q000737:chemistry; D014158:Transcription, Genetic
C525030:CST3 protein, human; D055316:Cystatin C; D015891:Cystatins; D015853:Cysteine Proteinase Inhibitors; D012333:RNA, Messenger; D013006:Growth Hormone