Storage proteins
- Pronunciation
- /STOR-ij PRO-teenz/
- Category
- Physiology
- Singular
- storage protein
- Plural
- storage proteins
Definition
A class of abundant, soluble proteins synthesized primarily during larval development and sequestered in insect or to serve as reserves for , , and . These hexameric proteins (typically 70–90 kDa subunits) are released from storage during non-feeding life stages when dietary intake ceases. In insects, they belong to several superfamilies including arylphorins, methionine-rich proteins, and female-specific very high- lipoproteins (VHDL), each with distinct amino acid compositions suited to specific developmental demands. Arachnids and other employ analogous storage strategies, though with less characterized protein .
Etymology
From English 'storage' (reservation for future use) + 'protein' (Greek proteios, 'primary' or 'holding first place'), reflecting their role as deferred nutrient capital.
Example
In the Manduca sexta, larvae accumulate massive quantities of arylphorin in during the final instar; this storage protein is subsequently endocytosed by and later mobilized to provision tissues and during the non-feeding pupal and adult stages.
Synonyms
- hexamerin
- larval serum protein
- arylphorin (specific type)
Related Terms
- Hemolymph
- Fat body
- Metamorphosis
- Diapause
- Vitellogenin
- hexamerin
- Juvenile hormone
- Ecdysone
- nutrient allocation
- protein metabolism
Usage Notes
Distinguish from structural proteins (permanent architectural components) and enzymatic proteins (catalytic). In entomology, 'storage protein' often specifically denotes hexameric larval serum proteins, whereas —though also a storage/transport protein—is usually treated separately due to its female-specific reproductive role. The term 'hexamerin' emphasizes the quaternary structure and is sometimes preferred in comparative studies. Storage proteins are developmentally regulated, with synthesis typically peaking just before wandering and entry into .