Analysis of proteome dynamics inside the silk gland lumen of Bombyx mori.
The silk gland is the only organ where silk proteins are synthesized and secreted in the silkworm, Bombyx mori. Silk proteins are stored in the lumen of the silk gland for around eight days during the fifth instar. Determining their dynamic changes is helpful for clarifying the secretion mechanism of silk proteins. Here, we identified the proteome in the silk gland lumen using liquid chromatography-tandem mass spectrometry, and demonstrated its changes during two key stages. From day 5 of the fifth instar to day 1 of wandering, the abundances of fibroins, sericins, seroins, and proteins of unknown functions increased significantly in different compartments of the silk gland lumen. As a result, these accumulated proteins constituted the major cocoon components. In contrast, the abundances of enzymes and extracellular matrix proteins decreased in the silk gland lumen, suggesting that they were not the structural constituents of silk. Twenty-five enzymes may be involved in the regulation of hormone metabolism for proper silk gland function. In addition, the metabolism of other non-proteinous components such as chitin and pigment were also discussed in this study.
State Key Laboratory of Silkworm Genome Biology, Southwest University, 2, Tiansheng Road, Beibei, Chongqing 400716, China.
Zhaoming
Z
Dong
State Key Laboratory of Silkworm Genome Biology, Southwest University, 2, Tiansheng Road, Beibei, Chongqing 400716, China.
Ping
P
Zhao
State Key Laboratory of Silkworm Genome Biology, Southwest University, 2, Tiansheng Road, Beibei, Chongqing 400716, China.
Yan
Y
Zhang
State Key Laboratory of Silkworm Genome Biology, Southwest University, 2, Tiansheng Road, Beibei, Chongqing 400716, China.
Qianru
Q
Song
State Key Laboratory of Silkworm Genome Biology, Southwest University, 2, Tiansheng Road, Beibei, Chongqing 400716, China.
Xiaolu
X
Zhang
State Key Laboratory of Silkworm Genome Biology, Southwest University, 2, Tiansheng Road, Beibei, Chongqing 400716, China.
Pengchao
P
Guo
State Key Laboratory of Silkworm Genome Biology, Southwest University, 2, Tiansheng Road, Beibei, Chongqing 400716, China.
Dandan
D
Wang
State Key Laboratory of Silkworm Genome Biology, Southwest University, 2, Tiansheng Road, Beibei, Chongqing 400716, China.
Qingyou
Q
Xia
D000818:Animals; D012831:Bombyx / Q000254:growth & development / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D004798:Enzymes / Q000032:analysis / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000032:analysis / Q000378:metabolism; D005349:Fibroins / Q000032:analysis / Q000378:metabolism; D019476:Insect Proteins / Q000032:analysis* / Q000378:metabolism; D007814:Larva / Q000378:metabolism; D008018:Life Cycle Stages; D020543:Proteome / Q000032:analysis* / Q000378:metabolism; D047030:Sericins / Q000032:analysis / Q000378:metabolism; D053719:Tandem Mass Spectrometry
D004798:Enzymes; D016326:Extracellular Matrix Proteins; D019476:Insect Proteins; D020543:Proteome; D047030:Sericins; D005349:Fibroins