Recombinant Bovine Peroxisomal membrane protein 11B (PEX11B)

Introduction

Peroxisomal membrane proteins, including Recombinant Bovine Peroxisomal membrane protein 11B (PEX11B), play a crucial role in peroxisome proliferation by regulating the elongation, constriction, and division of pre-existing peroxisomes . Peroxisomes are essential organelles in eukaryotic cells that perform complex metabolic and catabolic functions vital for normal growth and development .

Gene and Protein Structure

PEX11B, also known as Peroxisomal Biogenesis Factor 11 Beta, is a gene that encodes a protein involved in peroxisome biogenesis . The protein encoded by this gene belongs to the PEX11 family, which plays a critical role in peroxisome division . The human PEX11B gene (ENSG00000131779) has 3 transcripts (splice variants) and is associated with 5 phenotypes .

Function

PEX11 proteins are unique in their ability to promote peroxisome division . Overexpression of PEX11 proteins promotes peroxisome division even in the absence of peroxisomal metabolic activity . Mouse cells lacking PEX11B display reduced peroxisome abundance, even without peroxisomal metabolic substrates, and are partially deficient in ether lipid synthesis and very long chain fatty acid oxidation . PEX11B affects peroxisome metabolism indirectly, potentially due to altered membrane structure or dynamics .

Role in Neural Differentiation

Loss of PEX11B expression leads to a significant decrease in the expression of peroxisomal-related genes, including ACOX1, PMP70, PEX1, and PEX7, as well as neural tube-like structures and neuronal markers .

Knockdown of PEX11B reduces the expression of neural tube and neuronal markers and peroxisomal-related genes . The relative expression levels of neural progenitor markers SOX1 and PAX6, as well as the neuronal marker TUJ1, are reduced upon PEX11B knockdown . Dox-induced knockdown of PEX11B significantly decreases the expression levels of PEX1, PEX3, PMP70, PEX7, and ACOX1, but not PEX13 .

PEX11B and Peroxisome Biogenesis Disorders (PBD)

Mutations in 14 genes cause a spectrum of peroxisomal diseases in humans . PEX11B has been associated with an atypical peroxisome biogenesis disorder (PBD) . Peroxisome biogenesis disorder 14B (PBD14B) is an autosomal recessive peroxisome biogenesis disorder characterized clinically by mild intellectual disability, congenital cataracts, progressive hearing loss, and polyneuropathy .

PEX11B-Mediated Peroxisomal Proliferation

Pex11p family proteins are essential for peroxisomal fission, but their molecular mechanisms remain largely unknown . Overexpression of Pex11pβ causes substantial vesiculation of peroxisomes in mammalian cells . This vesicle formation depends on dynamin-like protein 1 (DLP1) and mitochondrial fission factor (Mff), as knockdown of these proteins diminishes peroxisomal fission after Pex11pβ overexpression .