Cloning of cDNA coding for connective tissue activating peptide III from a human platelet-derived lambda gt11 expression library.
We report here the cloning of the cDNA coding for platelet connective tissue-activating peptide-III (CTAP-III) from a lambda gt11 expression library prepared using messenger RNA (mRNA) isolated from human platelets. The open reading frame of the clone coded for a protein with 128 amino acid residues. Since the precursor of CTAP-III, platelet basic protein (PBP is 94 amino acids long, the 5'-translated region of the cDNA codes for a leader sequence 34 amino acids long. This leader sequence, like the sequence of mature CTAP-III, shows significant homology to the sequence of platelet factor 4 (PF4), the only other platelet specific alpha-granule protein cloned until now, from a human erythroleukemic (HEL) cell line-derived cDNA library. These leader sequences are probably critical for targeting such proteins to the alpha-granule. Northern blot hybridization with platelet and megakaryocyte mRNA shows a single species mRNA of approximately 0.8 kb, suggesting that the corresponding cDNA is full length. The cloning of platelet specific CTAP-III provides additional evidence for the platelet specificity of the cDNA library used.
Wenger
R H
RH
Theodor Kocher Institute, University of Berne, Switzerland.
Wicki
A N
AN
Walz
A
A
Kieffer
N
N
Clemetson
K J
KJ
D000595:Amino Acid Sequence; D001483:Base Sequence; D001792:Blood Platelets / Q000502:physiology*; D015152:Blotting, Northern; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D008969:Molecular Sequence Data; D010455:Peptides / Q000235:genetics*; D010978:Platelet Factor 4 / Q000235:genetics; D011498:Protein Precursors / Q000235:genetics
D010455:Peptides; D011498:Protein Precursors; D010978:Platelet Factor 4; C009862:connective tissue-activating peptide; D004247:DNA