cDNA cloning of murine interleukin-HP1: homology with human interleukin 6.
Interleukin-HP1 (HP1) is a murine T cell-derived lymphokine, originally described as a growth factor for B cell hybridomas and plasmacytomas, that was recently shown to stimulate growth and differentiation of normal B and T lymphocytes. Here, we describe a cDNA for HP1 that was isolated from a library prepared using mRNA of a murine helper T cell clone activated with a clonotypic antibody. The cDNA, which hybridizes with a mRNA of approximately 1300 bp, encodes a polypeptide consisting of 211 amino acids with a typical signal sequence of 24 residues followed by 187 amino acids, which form the mature protein (Mr = 21,710). No N-glycosylation site but several potential O-glycosylation sites were identified in the predicted sequence. Comparison of the cDNA sequence of HP1 with that of human interleukin 6 disclosed a homology of 65% at the DNA level and of 42% at the protein level with a maximum of 57% for the segment spanning residues 42-102 of mature HP1. Considering the functional homology that was previously established between these two proteins, we therefore propose that HP1 be renamed murine interleukin 6.
Van Snick
J
J
Ludwig Institute for Cancer Research, Brussels Branch, Belgium.
Cayphas
S
S
Szikora
J P
JP
Renauld
J C
JC
Van Roost
E
E
Boon
T
T
Simpson
R J
RJ
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000302:isolation & purification*; D006801:Humans; D015850:Interleukin-6; D007378:Interleukins / Q000235:genetics* / Q000302:isolation & purification; D051379:Mice; D008969:Molecular Sequence Data; D011498:Protein Precursors / Q000235:genetics / Q000302:isolation & purification; D021382:Protein Sorting Signals / Q000235:genetics / Q000302:isolation & purification; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D006377:T-Lymphocytes, Helper-Inducer / Q000032:analysis
D015850:Interleukin-6; D007378:Interleukins; D011498:Protein Precursors; D021382:Protein Sorting Signals; D004247:DNA