Molecular cloning, sequence, expression, and processing of the interleukin 16 precursor.
Interleukin 16 (IL-16) has been shown to function as chemoattractant factor, as a modulator of T-cell activation, and as an inhibitor of immunodeficiency virus replication. The recent identification of inconsistencies in published IL-16 cDNA nucleotide sequences led to the proposal that IL-16 is synthesized in the form of a large precursor protein (pro-IL-16). To identify the true transcriptional start of the IL-16 mRNA rapid amplification of cDNA ends methods were applied. The complete pro-IL-16 cDNA was subsequently molecularly cloned, sequenced, and expressed in COS-7 cells. We report here that pro-IL-16 is most likely synthesized as a 67-kDa protein and is encoded from a major 2.6-kb transcript. Recombinant pro-IL-16 polypeptides are specifically cleaved in lysates of CD8(+) cells, suggesting that the naturally secreted bioactive form of IL-16 is smaller than the originally published 130 amino acids fragment. Moreover, in contrast to other interleukins such as IL-15, IL-16 mRNA expression is almost exclusively limited to lymphatic tissues underlining the potential of IL-16 as an immune regulatory molecule.
Baier
M
M
Paul-Ehrlich-Institut, Paul-Ehrlich-Strasse 51-59, 63225 Langen, Germany. M.Baier@em.uni-frankfurt.de
Bannert
N
N
Werner
A
A
Lang
K
K
Kurth
R
R
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers; D018076:DNA, Complementary; D006801:Humans; D019410:Interleukin-16 / Q000096:biosynthesis* / Q000737:chemistry / Q000378:metabolism; D008214:Lymphocytes / Q000276:immunology*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D016133:Polymerase Chain Reaction; D011498:Protein Precursors / Q000096:biosynthesis* / Q000737:chemistry / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D012333:RNA, Messenger / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism; D014158:Transcription, Genetic
D017931:DNA Primers; D018076:DNA, Complementary; D019410:Interleukin-16; D011498:Protein Precursors; D012333:RNA, Messenger; D011994:Recombinant Proteins; C105950:interleukin 16 precursor