Interactive domains for chaperone activity in the small heat shock protein, human alphaB crystallin.
Protein pin arrays identified seven interactive sequences for chaperone activity in human alphaB crystallin using natural lens proteins, beta(H) crystallin and gammaD crystallin, and in vitro chaperone target proteins, alcohol dehydrogenase and citrate synthase. The N-terminal domain contained two interactive sequences, (9)WIRRPFFPFHSP(20) and (43)SLSPFYLRPPSFLRAP(58). The alpha crystallin core domain contained four interactive sequences, (75)FSVNLDVK(82) (beta3), (113)FISREFHR(120), (131)LTITSSLS(138) (beta8), and (141)GVLTVNGP(148) (beta9). The C-terminal domain contained one interactive sequence, (157)RTIPITRE(164), that included the highly conserved I-X-I/V motif. Two interactive sequences, (73)DRFSVNLDVKHFS(85) and (131)LTITSSLSDGV(141), belonging to the alpha crystallin core domain were synthesized as peptides and assayed for chaperone activity in vitro. Both synthesized peptides inhibited the thermal aggregation of beta(H) crystallin, alcohol dehydrogenase, and citrate synthase in vitro. Five of the seven chaperone sequences identified by the pin arrays overlapped with sequences identified previously as sequences for subunit-subunit interactions in human alphaB crystallin. The results suggested that interactive sequences in human alphaB crystallin have dual roles in subunit-subunit assembly and chaperone activity.
Ghosh
Joy G
JG
Biomolecular Structure and Design, University of Washington, Seattle, Washington 98195-7420, USA.
Estrada
Marcus R
MR
Clark
John I
JI
D000426:Alcohol Dehydrogenase / Q000737:chemistry; D000595:Amino Acid Sequence; D001665:Binding Sites; D002950:Citrate (si)-Synthase / Q000737:chemistry; D003459:Crystallins; D006801:Humans; D007381:Intermediate Filament Proteins / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000378:metabolism; D040081:Protein Array Analysis; D011494:Protein Kinases / Q000737:chemistry* / Q000378:metabolism; D017434:Protein Structure, Tertiary; D038203:alpha-Crystallin B Chain / Q000737:chemistry* / Q000378:metabolism; D038204:beta-Crystallins / Q000737:chemistry; D038222:gamma-Crystallins
C059215:CRYAB protein, human; C504903:CRYGD protein, human; D003459:Crystallins; D007381:Intermediate Filament Proteins; D009419:Nerve Tissue Proteins; D038203:alpha-Crystallin B Chain; D038204:beta-Crystallins; D038222:gamma-Crystallins; D000426:Alcohol Dehydrogenase; D002950:Citrate (si)-Synthase; D011494:Protein Kinases