Human CSF-1: Molecular Cloning and Expression of 4-kb cDNA Encoding the Human Urinary Protein

Abstract

A 4-kilobase complementary DNA (cDNA) encoding human macrophage-specific colony-stimulating factor (CSF-1) was isolated. When introduced into mammalian cells, this cDNA directs the expression of CSF-1 that is structurally and functionally indistinguishable from the natural human urinary CSF-1. Direct structural analysis of both the recombinant CSF-1 and the purified human urinary protein revealed that these species contain a sequence of at least 40 amino acids at their carboxyl termini which are not found in the coding region of a 1.6-kilobase CSF-1 cDNA that was previously described. These results demonstrate that the human CSF-1 gene can be expressed to yield at least two different messenger RNA species that encode distinct but related forms of CSF-1.

Macrophage colony‐stimulating factor purified from normal human urine Amino‐terminal sequence and amino acid composition

“…The N-terminal amino acid sequence we determined was consistent with that deduced by other workers [2,3] except for a single difference at position 37: we found Ser instead of Phe at this position. The replacement of Ser-37 by Phe can be explained by the change of the Ser codon to a Phe codon via a single base replacement in the eDNA clone.…”

“…The sequence deduced by Kawasaki et al [2] is nearly consistent with that deduced by Wong et al [3] between position 1 and position 148. However, the latter sequence contains an additional sequence of 295 residues intervening between position 148 and position 149 of the former.…”

“…The amino acid composition of our M-CSF preparation most closely fits the sequence deduced by Wong et al [3] when the integral value for each residue is calculated on the basis of the assumption that the molecule contains 5 His residues. On the other hand, the sequence deduced by Kawasaki et al [2] does not match well with the result of our determination.…”

“…The analytical values are expressed as mol individual amino acid per mol His, and the number of residues of each amino acid was calculated with respect to the integral value of His being 4 or 5. Table 2 also shows the number of amino acid residues present in the sequence deduced by other workers [2,3].…”

“…The total amino acid sequence of human M-CSF was deduced by Kawasaki et al [2] as well as by Wong et al [3] from the nucleotide sequence of complementary DNA (cDNA) clones derived from human tumor cell lines. The sequence deduced by Kawasaki et al [2] is nearly consistent with that deduced by Wong et al [3] between position 1 and position 148.…”