Decreased stability and translation of T cell receptor zeta mRNA with an alternatively spliced 3'-untranslated region contribute to zeta chain down-regulation in patients with systemic lupus erythematosus.
The molecular mechanisms involved in the aberrant expression of T cell receptor (TCR) zeta chain of patients with systemic lupus erythematosus are not known. Previously we demonstrated that although normal T cells express high levels of TCR zeta mRNA with wild-type (WT) 3' untranslated region (3' UTR), systemic lupus erythematosus T cells display significantly high levels of TCR zeta mRNA with the alternatively spliced (AS) 3' UTR form, which is derived by splice deletion of nucleotides 672-1233 of the TCR zeta transcript. Here we report that the stability of TCR zeta mRNA with an AS 3' UTR is low compared with TCR zeta mRNA with WT 3' UTR. AS 3' UTR, but not WT 3' UTR, conferred similar instability to the luciferase gene. Immunoblotting of cell lysates derived from transfected COS-7 cells demonstrated that TCR zeta with AS 3' UTR produced low amounts of 16-kDa protein. In vitro transcription and translation also produced low amounts of protein from TCR zeta with AS 3' UTR. Taken together our findings suggest that nucleotides 672-1233 bp of TCR zeta 3' UTR play a critical role in its stability and also have elements required for the translational regulation of TCR zeta chain expression in human T cells.
Chowdhury
Bhabadeb
B
Department of Cellular Injury, Walter Reed Army Institute of Research, Silver Spring, Maryland 20910-7500, USA.
Tsokos
Christos G
CG
Krishnan
Sandeep
S
Robertson
James
J
Fisher
Carolyn U
CU
Warke
Rahul G
RG
Warke
Vishal G
VG
Nambiar
Madhusoodana P
MP
Tsokos
George C
GC
D020413:3' Untranslated Regions; D017398:Alternative Splicing; D000818:Animals; D019556:COS Cells; D003001:Cloning, Molecular; D017931:DNA Primers / Q000737:chemistry; D003720:Densitometry; D015536:Down-Regulation; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D006801:Humans; D015151:Immunoblotting; D019169:Jurkat Cells; D008156:Luciferases / Q000378:metabolism; D008180:Lupus Erythematosus, Systemic / Q000378:metabolism*; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism; D014176:Protein Biosynthesis; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000378:metabolism*; D011948:Receptors, Antigen, T-Cell / Q000737:chemistry* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000378:metabolism; D013997:Time Factors; D014158:Transcription, Genetic; D014162:Transfection
D020413:3' Untranslated Regions; D017931:DNA Primers; D008565:Membrane Proteins; D012333:RNA, Messenger; D011948:Receptors, Antigen, T-Cell; C054979:antigen T cell receptor, zeta chain; D008156:Luciferases