Hsp25, a member of the Hsp30 family, promotes inclusion formation in response to stress.
Protein aggregates are oligomeric complexes of misfolded proteins, and serve as the seeds of inclusion bodies termed aggresomes in the cells. Heat shock proteins (Hsps) prevent misfolding and aggregate formation. Here, we found that only avian Hsp25 dominantly accumulated in the aggresomes induced by proteasome inhibition. Molecular cloning of chicken Hsp25 (cHsp25) revealed that it belongs to the Hsp30 family, which is a subfamily of the alpha-crystallin/small Hsp gene family. Unexpectedly, overexpression of cHsp25 into HeLa cells promoted inclusion formation whereas overexpression of mouse Hsp27 and its chicken homologue did not. These results suggest that cHsp25 acts differently from other small Hsps on protein aggregates.
Katoh
Yumiko
Y
Department of Biochemistry and Molecular Biology, Yamaguchi University School of Medicine, Minami-Kogushi 1-1-1, Ube 775-8505, Japan.
Fujimoto
Mitsuaki
M
Nakamura
Kosuke
K
Inouye
Sachiye
S
Sugahara
Kazuma
K
Izu
Hanae
H
Nakai
Akira
A
D000595:Amino Acid Sequence; D000818:Animals; D030161:Avian Proteins / Q000096:biosynthesis; D015153:Blotting, Western; D002645:Chickens; D003001:Cloning, Molecular; D003459:Crystallins / Q000737:chemistry; D018076:DNA, Complementary / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism; D055551:HSP27 Heat-Shock Proteins; D050890:HSP30 Heat-Shock Proteins; D006367:HeLa Cells; D006360:Heat-Shock Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000502:physiology*; D006801:Humans; D002479:Inclusion Bodies; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins / Q000502:physiology*; D008856:Microscopy, Fluorescence; D018832:Molecular Chaperones; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000737:chemistry / Q000502:physiology*; D010802:Phylogeny; D017510:Protein Folding; D017346:Protein Serine-Threonine Kinases / Q000096:biosynthesis; D011784:Quail; D017386:Sequence Homology, Amino Acid; D013312:Stress, Physiological; D025801:Ubiquitin / Q000737:chemistry; D000099190:MAP-Kinase-Activated Kinase 2
D030161:Avian Proteins; D003459:Crystallins; D018076:DNA, Complementary; D055551:HSP27 Heat-Shock Proteins; D050890:HSP30 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D018832:Molecular Chaperones; D009363:Neoplasm Proteins; D017346:Protein Serine-Threonine Kinases; D025801:Ubiquitin; D000099190:MAP-Kinase-Activated Kinase 2; C057725:HSPB1 protein, human