Molecular Cloning of a Novel Glutelin cDNA from Rice Seeds.

Abstract

A novel glutelin gene was cloned from a cDNA library of maturing rice seeds (Oryza sativa L. cv Nipponbare) . The 2.0kbp insert contained an open reading frame encoding a 510 amino acid polypeptide (Mr 57,116). This novel glutelin shares 46 to 49% amino acid identity with previously identified rice glutelins. A phylogenetic analysis of cloned glutelins indicates that this gene constitutes a new, fifth class of glutelin gene families. The Asn-Gly processing sequence which is highly conserved in 11S seed storage proteins is replaced by Asn-Val in the sequence of the novel glutelin. The amino acid composition extending 50 residues both upstream and downstream of the Asn-Val site was less hydrophilic than in other glutelins. The N-terminal half corresponding to the acidic domains of other glutelins possesses a higher pI value (7.46) than found in other glutelins. Expression of the gene was detected in maturing seeds, but not in roots or leaves.

Molecular and environmental factors determining grain quality in rice

“…A recent transcriptional profiling study of six members from the GluA and GluB subfamilies showed that none of them had any detectable expression level at three DAF but with a peak activity at 10 DAF before declining toward maturation (20 DAF) (Duan and Sun 2005). This common pattern was also discovered in other studies on GluA, GluB, and GluC subfamily members (Okita et al 1989;Takaiwa andOono 1990, 1991;Mitsukawa et al 1998). GluD-1, however, is different from the other glutelin genes.…”

“…; Takaiwa and Oono , ; Mitsukawa et al. ). GluD‐1 , however, is different from the other glutelin genes.…”

“…Encoded by about 15 genes per haploid genome, glutelin genes can be classified into four subfamilies: GluA, B, C, and D. GluA has four members, whereas GluB has the highest with eight members. Thus far, only two members of GluC and one member of the GluD subfamily have been identified (Takaiwa 1987;Okita et al 1989;Mitsukawa et al 1998;Kusaba et al 2003;Katsube-Tanaka et al 2004;Kawakatsu et al 2008). As the second most abundant protein in rice endosperm, the prolamins have molecular masses ranging from 12 to 17 kDa.…”

Cereal seed storage protein synthesis: fundamental processes for recombinant protein production in cereal grains

“…, 1982) (Figure 2). Processing sites (Asn‐Gly) are highly conserved, but there are some deviations, such as Asn‐Val in GluC (Mitsukawa et al. , 1998).…”

“…After trafficking to the PB-II as trimers by two routes, proglutelins are processed by vacuolar protein enzyme (VPE), generating both the mature acidic and the basic subunits that are linked by a disulphide bond Yamagata et al, 1982) (Figure 2). Processing sites (Asn-Gly) are highly conserved, but there are some deviations, such as Asn-Val in GluC (Mitsukawa et al, 1998). When GluA-2 was mutated to a noncleavable form, deposition was not affected, but higher-order structure formation was perturbed .…”