Cloning and molecular characterization of a cDNA encoding a small GTPase from Hevea brasiliensis.

Small GTPases play a critical role in the regulation of a range of cellular processes including growth, differentiation, and intracellular transportation. The cDNA encoding a small GTPase, designated as HbGTPase1, was isolated from Hevea brasiliensis. HbGTPase1 was 882 bp long containing a 612-bp open reading frame encoding a putative protein of 203 amino acids, flanked by an 83-bp 5'-untranslated region (UTR) and a 187-bp 3'-UTR. The predicted molecular mass of HbGTPase1 is 22.62 kDa, with an isoelectric point of 5.06. The HbGTPase1 protein was predicted to possess the conserved functional regions of the small GTPase superfamily of proteins. Quantitative polymerase chain reaction analysis revealed that HbGTPase1 was constitutively expressed in all tissues tested. HbGTPase1 transcripts accumulated at relatively low levels in the flower, latex, and leaves, while HbGTPase1 transcripts accumulated at relatively high levels in bark. Transcription of HbGTPase1 in the latex was induced by jasmonate.