Datasheet

生物学的記述

Specificity	DNAJC2/MPP11 Antibody (Rabbit mAb) [B7H1] detects endogenous levels of total DNAJC2/MPP11 proteins.
Background	DNAJC2 (also called MPP11 or ZUOTIN) is the mammalian ortholog of the yeast Hsp40-family chaperone Zuotin, and it is characterized by an N-terminal zuotin-homology domain fused to a C-terminal two-repeat Myb domain, with MPP11 localizing to the cytosol and physically associating with ribosomes. In yeast, Zuotin partners with the atypical Hsp70 homolog Ssz1 to form a stable heterodimer termed the ribosome-associated complex (RAC), which in turn functions as the J-domain cochaperone partner of the soluble ribosome-associated Hsp70 Ssb, stimulating Ssb's ATPase activity to facilitate co-translational folding of nascent polypeptide chains as they emerge from the ribosome exit tunnel. Biochemical purification of human MPP11 revealed that it forms an analogous stable complex with Hsp70L1, a distantly related mammalian homolog of yeast Ssz1, and this human MPP11-Hsp70L1 complex comigrates with polysomes and ribosomes on sucrose density gradients in a salt-sensitive manner, forming a roughly 200-kDa dimeric assembly; complementation experiments directly demonstrate that this mammalian ribosome-associated complex can rescue growth defects in yeast strains genetically lacking a functional RAC, establishing that the ribosome-tethered chaperone function performed by Zuotin-Ssz1 in yeast is conserved, despite substantial sequence divergence, as MPP11-Hsp70L1 in mammalian cells. Structural analysis of the yeast Zuo1 protein shows it makes dual contacts across both ribosomal subunits, with its C-terminal four-helix bundle engaging the 40S subunit near an expansion segment of the 18S rRNA close to the decoding site while its zuotin-homology domain contacts the 60S subunit near the peptide exit tunnel, spanning the ribosome to position its J-domain appropriately for partner Hsp70 activation, and further work shows that Zuotin exists in an autoinhibited conformation on nascent-chain-free ribosomes that undergoes large-scale structural remodeling once a nascent chain reaches the tunnel exit, exposing the J-domain to its Hsp70 partner. Because MPP11 depletion in human cells produces growth defects that closely resemble those of yeast strains lacking RAC, and because this ribosome-associated chaperone network is now understood to connect to a broader set of cochaperone and quality-control factors in human cells, DNAJC2/MPP11 is established as a conserved, functionally essential component of the co-translational protein folding machinery operating at the ribosomal exit tunnel.

Specificity

DNAJC2/MPP11 Antibody (Rabbit mAb) [B7H1] detects endogenous levels of total DNAJC2/MPP11 proteins.

Background

DNAJC2 (also called MPP11 or ZUOTIN) is the mammalian ortholog of the yeast Hsp40-family chaperone Zuotin, and it is characterized by an N-terminal zuotin-homology domain fused to a C-terminal two-repeat Myb domain, with MPP11 localizing to the cytosol and physically associating with ribosomes. In yeast, Zuotin partners with the atypical Hsp70 homolog Ssz1 to form a stable heterodimer termed the ribosome-associated complex (RAC), which in turn functions as the J-domain cochaperone partner of the soluble ribosome-associated Hsp70 Ssb, stimulating Ssb's ATPase activity to facilitate co-translational folding of nascent polypeptide chains as they emerge from the ribosome exit tunnel. Biochemical purification of human MPP11 revealed that it forms an analogous stable complex with Hsp70L1, a distantly related mammalian homolog of yeast Ssz1, and this human MPP11-Hsp70L1 complex comigrates with polysomes and ribosomes on sucrose density gradients in a salt-sensitive manner, forming a roughly 200-kDa dimeric assembly; complementation experiments directly demonstrate that this mammalian ribosome-associated complex can rescue growth defects in yeast strains genetically lacking a functional RAC, establishing that the ribosome-tethered chaperone function performed by Zuotin-Ssz1 in yeast is conserved, despite substantial sequence divergence, as MPP11-Hsp70L1 in mammalian cells. Structural analysis of the yeast Zuo1 protein shows it makes dual contacts across both ribosomal subunits, with its C-terminal four-helix bundle engaging the 40S subunit near an expansion segment of the 18S rRNA close to the decoding site while its zuotin-homology domain contacts the 60S subunit near the peptide exit tunnel, spanning the ribosome to position its J-domain appropriately for partner Hsp70 activation, and further work shows that Zuotin exists in an autoinhibited conformation on nascent-chain-free ribosomes that undergoes large-scale structural remodeling once a nascent chain reaches the tunnel exit, exposing the J-domain to its Hsp70 partner. Because MPP11 depletion in human cells produces growth defects that closely resemble those of yeast strains lacking RAC, and because this ribosome-associated chaperone network is now understood to connect to a broader set of cochaperone and quality-control factors in human cells, DNAJC2/MPP11 is established as a conserved, functionally essential component of the co-translational protein folding machinery operating at the ribosomal exit tunnel.

使用情報

Application

WB, IP

Dilution

WB	IP
1:1000	1:50

Reactivity

Human, Mouse, Rat, Monkey

Source

Rabbit Monoclonal Antibody

MW

72 kDa

Storage Buffer

PBS, pH 7.2+50% Glycerol+0.05% BSA+0.01% NaN3

Storage
(from the date of receipt)

-20°C (avoid freeze-thaw cycles), 2 years

プロトコール

References

https://pubmed.ncbi.nlm.nih.gov/16002468/
https://pubmed.ncbi.nlm.nih.gov/21245388/

DNAJC2/MPP11 Antibody (Rabbit mAb) [B7H1]

生物学的記述

使用情報

References

Application Data