Search Results

Overview

Uniprot IDQ6S4N2
Protein NameHeat shock 70 kDa protein 1B
Gene NameHSPA1B
OrganismSus scrofa

Kla Sites from experimental identification

Position Flanking peptide
100 RVINDGDKPKVQVSY
108 PKVQVSYKGETKAFY
246 NHFVEEFKRKHKKDI
251 EFKRKHKKDISQNKR
257 KKDISQNKRAVRRLR
328 LRDAKLDKAQIHDLV
500 KSTGKANKITITNDK
512 NDKGRLSKEEIERMV
526 VQEAEKYKAEDEIQR
56 RLIGDAAKNQVALNP
71 QNTVFDAKRLIGRKF

Function

Molecular chaperone implicated in a wide variety of cellular processes, including protection of the proteome from stress, folding and transport of newly synthesized polypeptides, activation of proteolysis of misfolded proteins and the formation and dissociation of protein complexes. Plays a pivotal role in the protein quality control system, ensuring the correct folding of proteins, the re-folding of misfolded proteins and controlling the targeting of proteins for subsequent degradation. This is achieved through cycles of ATP binding, ATP hydrolysis and ADP release, mediated by co-chaperones. The co-chaperones have been shown to not only regulate different steps of the ATPase cycle, but they also have an individual specificity such that one co-chaperone may promote folding of a substrate while another may promote degradation. The affinity for polypeptides is regulated by its nucleotide bound state. In the ATP-bound form, it has a low affinity for substrate proteins. However, upon hydrolysis of the ATP to ADP, it undergoes a conformational change that increases its affinity for substrate proteins. It goes through repeated cycles of ATP hydrolysis and nucleotide exchange, which permits cycles of substrate binding and release. The co-chaperones are of three types: J-domain co-chaperones such as HSP40s (stimulate ATPase hydrolysis by HSP70), the nucleotide exchange factors (NEF) such as BAG1/2/3 (facilitate conversion of HSP70 from the ADP-bound to the ATP-bound state thereby promoting substrate release), and the TPR domain chaperones such as HOPX and STUB1. Maintains protein homeostasis during cellular stress through two opposing mechanisms: protein refolding and degradation. Its acetylation/deacetylation state determines whether it functions in protein refolding or protein degradation by controlling the competitive binding of co-chaperones HOPX and STUB1. During the early stress response, the acetylated form binds to HOPX which assists in chaperone-mediated protein refolding, thereafter, it is deacetylated and binds to ubiquitin ligase STUB1 that promotes ubiquitin-mediated protein degradation. Regulates centrosome integrity during mitosis, and is required for the maintenance of a functional mitotic centrosome that supports the assembly of a bipolar mitotic spindle. Enhances STUB1-mediated SMAD3 ubiquitination and degradation and facilitates STUB1-mediated inhibition of TGF-beta signaling. Essential for STUB1-mediated ubiquitination and degradation of FOXP3 in regulatory T-cells (Treg) during inflammation

Protein Sequence

10 MAKSVAIGID 20 LGTTYSCVGV 30 FQHGKVEIIA 40 NDQGNRTTPS 50 YVAFTDTERL 60 IGDAAKNQVA 70 LNPQNTVFDA 80 KRLIGRKFGD 90 PVVQADMKHW 100 PFRVINDGDK 110 PKVQVSYKGE 120 TKAFYPEEIS 130 SMVLTKMKEI 140 AEAYLGHPVS 150 NAVITVPAYF 160 NDSQRQATKD 170 AGVIAGLNVL 180 RIINEPTAAA 190 IAYGLDRTGK 200 GERNVLIFDL 210 GGGTFDVSIL 220 TIDDGIFEVK 230 ATAGDTHLGG 240 EDFDNRLVNH 250 FVEEFKRKHK 260 KDISQNKRAV 270 RRLRTACERA 280 KRTLSSSTQA 290 SLEIDSLFEG 300 IDFYTSITRA 310 RFEELCSDLF 320 RSTLEPVEKA 330 LRDAKLDKAQ 340 IHDLVLVGGS 350 TRIPKVQKLL 360 QDFFNGRDLN 370 KSINPDEAVA 380 YGAAVQAAIL 390 MGDKSENVQD 400 LLLLDVAPLS 410 LGLETAGGVM 420 TALIKRNSTI 430 PTKQTQIFTT 440 YSDNQPGVLI 450 QVYEGERAMT 460 RDNNLLGRFE 470 LSGIPPAPRG 480 VPQIEVTFDI 490 DANGILNVTA 500 TDKSTGKANK 510 ITITNDKGRL 520 SKEEIERMVQ 530 EAEKYKAEDE 540 IQRERVSAKN 550 ALESYAFNMK 560 SAVEDEGLKG 570 KISEADKKKV 580 LDKCQEVISW 590 LDANTLAEKD 600 EFEHKRKELE 610 QVCNPIISGL 620 YQGAGGPGAG 630 GFGAQAPKGG 640 SGSGPTIEEV D

Gene Ontology

Classification GO ID Description
Cellular Component GO:0005813 centrosome
Cellular Component GO:0005737 cytoplasm
Cellular Component GO:0005829 cytosol
Cellular Component GO:0005634 nucleus
Cellular Component GO:0005886 plasma membrane
Molecular Function GO:0005524 ATP binding
Molecular Function GO:0016887 ATP hydrolysis activity
Molecular Function GO:0031072 heat shock protein binding
Molecular Function GO:0044183 protein folding chaperone
Biological Process GO:0090063 positive regulation of microtubule nucleation
Biological Process GO:0032436 positive regulation of proteasomal ubiquitin-dependent protein catabolic process
Biological Process GO:0042026 protein refolding
Biological Process GO:1901673 regulation of mitotic spindle assembly

Reference

[1] Fan S, Zhou R, Wen H, Ye H, Ma S et al.. Global profiling of protein lactylome in porcine granulosa cells.. J Ovarian Res 18(1):177. 2025 Aug 8. PMID: 40781717.