Recombinant Candida glabrata Presequence translocated-associated motor subunit PAM17, mitochondrial (PAM17)
Description
Introduction
Recombinant Candida glabrata Presequence translocated-associated motor subunit PAM17, mitochondrial (PAM17) is a genetically engineered protein critical for studying mitochondrial protein import mechanisms in this pathogenic yeast. PAM17 is a non-essential subunit of the presequence translocase-associated motor (PAM) complex, which drives the ATP-dependent translocation of nuclear-encoded preproteins into the mitochondrial matrix . Its recombinant form enables biochemical and structural studies to elucidate its role in fungal pathogenicity and cellular homeostasis.
Biological Role in Mitochondrial Protein Import
PAM17 regulates the TIM23-PAM complex, which mediates the translocation of presequence-containing proteins into the mitochondrial matrix. Key functions include:
-
Stabilizing the Pam16-Pam18 subcomplex: PAM17 ensures proper assembly of the J-protein complex, which activates mitochondrial Hsp70 (mtHsp70) to drive preprotein translocation .
-
Modulating TIM23-PAM interactions: Inactivation of Tim44 (a PAM scaffold protein) enhances PAM17’s association with the TIM23 complex, suggesting competitive binding dynamics .
-
Post-translational import regulation: PAM17 facilitates early-stage polypeptide binding to mtHsp70, while Tim44 assists in later translocation steps .
Functional Insights from Yeast Models
Studies in Saccharomyces cerevisiae homologs reveal conserved mechanisms relevant to C. glabrata:
-
Genetic interactions: Deletion of PAM17 synthetically enhances growth defects in tim44 or ssc1 (mtHsp70) mutants, indicating cooperative roles in protein import .
-
Import defects: pam17Δ mitochondria show impaired matrix protein import (e.g., F1β ATPase subunit) but retain inner membrane sorting activity for proteins like cytochrome c1 .
-
Motor activity: PAM17 is required for the ATP-dependent “pulling” force exerted by mtHsp70 during preprotein translocation .
Recombinant Production and Applications
The recombinant protein is commercially available for research purposes (e.g., MyBioSource MBS7087263 , Creative Biomart RFL13889CF ). Key uses include:
-
Mechanistic studies: Investigating PAM17’s role in fungal mitochondrial physiology and stress adaptation.
-
Drug discovery: Screening inhibitors targeting mitochondrial import in C. glabrata, a pathogen resistant to azoles and amphotericin B .
Research Findings and Key Studies
Future Directions
-
Structural resolution: Cryo-EM studies of recombinant PAM17 bound to TIM23-PAM components could clarify its regulatory interfaces.
-
Pathogenicity links: Investigating whether PAM17 influences C. glabrata’s virulence or drug resistance via mitochondrial stress pathways .
-
Therapeutic targeting: Developing PAM17 inhibitors to disrupt fungal mitochondrial function without affecting human homologs.
Product Specs
Note: While we prioritize shipping the format currently in stock, please specify your format preference during order placement for customized preparation.
Note: All proteins are shipped with standard blue ice packs unless dry ice shipping is specifically requested in advance. Additional fees apply for dry ice shipping.
The tag type is determined during production. If you require a specific tag, please inform us, and we will prioritize its development.
Target Background
KEGG: cgr:CAGL0M05929g
STRING: 284593.XP_449604.1
Q&A
Basic Research Questions
-
What is the role of PAM17 in Candida glabrata mitochondrial protein import?
PAM17 is a critical component of the Presequence translocase-Associated Motor (PAM) complex in Candida glabrata mitochondria. It functions as an inner membrane protein that is anchored in the mitochondrial inner membrane with its major domain exposed to the matrix . PAM17 is synthesized with a cleavable presequence and imported into mitochondria in a membrane potential (Δψ)-dependent manner .
Functionally, PAM17 is required specifically for the import of proteins destined for the mitochondrial matrix, while it is dispensable for the sorting of proteins to the inner membrane . This selective function demonstrates its specialized role in the complete translocation pathway rather than the arrest-transfer pathway of mitochondrial protein import.
-
How does PAM17 interact with other components of the mitochondrial import machinery?
PAM17 does not directly form a part of the Pam16-Pam18 complex but plays a critical role in organizing this complex and facilitating its association with the TIM23 complex . Research findings demonstrate that:
-
PAM17 migrates separately from the Pam16-Pam18 complex on Blue Native PAGE (BN-PAGE) at approximately 50 kDa, while the Pam16-Pam18 complex appears at about 80 kDa
-
In mitochondria lacking PAM17 (pam17Δ), the association of Pam16 and Pam18 with the TIM23 complex is significantly reduced
-
PAM17 works in concert with Tim17 to facilitate the association of multiple PAM subunits with the TIM23 complex
Experimental approaches to study these interactions typically involve co-immunoprecipitation with tagged components and BN-PAGE analysis of protein complexes isolated from mitochondria.
-
What phenotypes are observed in C. glabrata strains lacking PAM17?
C. glabrata cells with PAM17 deletion exhibit several distinctive phenotypes:
-
Slow growth on non-fermentable media, indicating compromised mitochondrial function
-
Strongly impaired import of matrix proteins, including F1β-ATPase subunit and b2(167)Δ-DHFR
-
Normal membrane potential generation, as measured by the potential-sensitive dye DiSC3(5)
-
Unaffected import of inner membrane-sorted proteins containing stop-transfer signals
-
Reduced levels of Pam18 protein when grown at elevated temperatures (37°C)
-
Impaired import-driving activity of PAM as measured by protease protection assays
These phenotypes collectively confirm PAM17's specific role in matrix protein import and PAM complex organization without affecting other aspects of mitochondrial bioenergetics.
