Scholarlink

Main conclusion <p>GmCP3 in soybean seed vacuoles is a candidate processing enzyme of β-conglycinin subunits. However, a different type of proteases may be involved in unconventional secretion of β-conglycinin propeptides.</p> Abstract <p>Soybean β-conglycinin subunits, a 7S vicilin class of seed storage proteins (SSPs) of seed vacuoles, are subject to proteolytic cleavage of the N-terminal propeptide for subunit maturation. Unlike other SSPs, this process is independent of asparagine residues. It occurs at the C-terminal of lysine residues, indicating the involvement of unidentified processing enzymes outside the vacuolar processing enzyme (VPE) family of proteases. In this study, we hypothesized that GmCP3, a seed-specific vacuolar protease belonging to the papain-like cysteine protease (PLCP) family, might be responsible for this process and analyzed the relationship between its accumulation and processing. The results showed that GmCP3 accumulated abundantly during the synthesis of β-conglycinin subunits and significantly decreased once the processing was complete. Immunoelectron microscopy of developing seed cells showed the accumulation of both, GmCP3 and β-conglycinin propeptides, in vacuolar-associated compartments, such as protein storage vacuoles (PSVs) and prevacuolar compartments (PVCs). Unexpectedly, labeling specific of the propeptide region of β-conglycinin subunits, but not the mature subunit region, was observed in extracellular regions. These results indicate that GmCP3 is a possible candidate β-conglycinin processing enzyme of vacuoles, though other proteases may have a role in the secretion of propeptides.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Proteases of vacuoles and other endomembrane compartments possibly involve proteolytic processing of soybean β-conglycinin subunits

  • 期刊论文

  • 发表日期：

    2026年1月15日

查看全文
  • Yuki Matsuoka,
  • Nobuyuki Maruyama

摘要

Main conclusion

GmCP3 in soybean seed vacuoles is a candidate processing enzyme of β-conglycinin subunits. However, a different type of proteases may be involved in unconventional secretion of β-conglycinin propeptides.

Abstract

Soybean β-conglycinin subunits, a 7S vicilin class of seed storage proteins (SSPs) of seed vacuoles, are subject to proteolytic cleavage of the N-terminal propeptide for subunit maturation. Unlike other SSPs, this process is independent of asparagine residues. It occurs at the C-terminal of lysine residues, indicating the involvement of unidentified processing enzymes outside the vacuolar processing enzyme (VPE) family of proteases. In this study, we hypothesized that GmCP3, a seed-specific vacuolar protease belonging to the papain-like cysteine protease (PLCP) family, might be responsible for this process and analyzed the relationship between its accumulation and processing. The results showed that GmCP3 accumulated abundantly during the synthesis of β-conglycinin subunits and significantly decreased once the processing was complete. Immunoelectron microscopy of developing seed cells showed the accumulation of both, GmCP3 and β-conglycinin propeptides, in vacuolar-associated compartments, such as protein storage vacuoles (PSVs) and prevacuolar compartments (PVCs). Unexpectedly, labeling specific of the propeptide region of β-conglycinin subunits, but not the mature subunit region, was observed in extracellular regions. These results indicate that GmCP3 is a possible candidate β-conglycinin processing enzyme of vacuoles, though other proteases may have a role in the secretion of propeptides.