An alternatively processed mRNA generated from human hepatocyte growth factor gene

Abstract

Kitamura, N. (1989) Biochem. Biophys. Res. Commun. 163, In the present study, we report the sequence of another cDNA clone for a shorter form of hHGF mRNA. Comparison of the sequence with that of the hHGF cDNA revealed that the two sequences are identical in their 5' ends up to 865 nucleotides downstream from the translation-initiation site, then completely diverge from each other. By Northern blot analysis, the hHGF-related 1.5-kb mRNA, which corresponded to the newly isolated cDNA variant, was identified in human placenta. Sequence analysis of a human genomic HGF clone showed that the diverged 3'-terminal portion of the mRNA is generated by alternative RNA-processing events utilizing a specific exon. The mRNA could encode a short hHGF molecule of 290 amino acids corresponding to the N-terminal portion of hHGF which consists of 728 amino acids. In order to examine the effect of the predicted translation product on hepatocyte growth, an expression plasmid for the cDNA variant was constructed and transfected into Cos cells. Immunoblotting analysis showed that the transfected Cos cells produced a protein of about 33 kDa. The protein product did not stimulate DNA synthesis by rat hepatocytes in primary culture.Hepatocyte growth factor (HGF) is a protein which stimulates the growth of adult rat hepatocytes in primary culture. HGF have been purified from the plasma of patients with fulminant hepatic failure [I], normal human plasma [2], rat platelet [3], and rabbit serum [2, 41. The purified HGF is a heterodimer consisting of heavy and light chains with molecular masses of about 65 kDa and 35 kDa, respectively. The entire amino acid sequences of human and rat HGF have been elucidated by sequence determinations of molecularly cloned cDNA [5 -81. The sequences showed that the heavy and light chains are produced from a single precursor by proteolytic processing. HGF consists of characteristic structural domains. One of these domains is four tandem repeats called kringles in the heavy chain region. The kringle structures are also present in several other proteins, such as plasminogen [9], prothrombin [lo], tissue plasminogen activator [I 11, urokinase [12], coagulation factor XI1 [I31 and apolipoprotein(a) [14]. The first kringle in plasminogen and the second kringle in

Concomitant Expression of Hepatocyte Growth Factor/Scatter Factor and the Receptor c-MET in Human Myeloma Cell Lines

“…The presence of these mRNA species, as well as the relative abundance of the bands as apparent in Fig. 7, corresponds closely with what has earlier been shown for human placenta mRNA (31), indicating that the transcription mechanism and RNA processing for the HGF gene in myeloma cells resembles the process taking place in placenta.…”

Fat Depot-Specific Differences in Angiogenic Growth Factor Gene Expression and Its Relation to Adipocyte Size in Cattle

“…In addition, no significant correlation was found between adipocyte size and HGF mRNA level. One explanation for these results might be the presence of splicing variants of HGF [28]. Bell et al [4] showed that there was no difference in the expression of HGF mRNA in subcutaneous adipocytes between lean and obese subjects.…”

Hepatocyte Growth Factor Activator Inhibitor, a Novel Kunitz-type Serine Protease Inhibitor

“…Human adult and fetal multiple tissue Northern blot membranes were purchased from Clontech. The membranes were hybridized at 42°C for 16 h with the 32 P-labeled probe as described (15). The membranes were washed with 1 ϫ SSC containing 1% SDS at 50°C.…”