Endophilin-B1 is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...

that in humans is encoded by the ''SH3GLB1''

gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...

. Endophilin-B1 belongs to the Bin/Amphiphysin/Rvs167 (

BAR Bar or BAR may refer to: Food and drink * Bar (establishment), selling alcoholic beverages * Candy bar ** Chocolate bar * Protein bar Science and technology * Bar (river morphology), a deposit of sediment * Bar (tropical cyclone), a laye ...

) family of proteins and plays a critical role in

mitochondrial fission Mitochondrial fission is the process by which mitochondria divide or segregate into two separate mitochondrial organelles. Mitochondrial fission is counteracted by mitochondrial fusion, where two mitochondria fuse together to form a larger one. Fu ...

and fusion, as well as in

autophagy Autophagy (or autophagocytosis; from the Greek language, Greek , , meaning "self-devouring" and , , meaning "hollow") is the natural, conserved degradation of the cell that removes unnecessary or dysfunctional components through a lysosome-depe ...

and

apoptosis Apoptosis (from ) is a form of programmed cell death that occurs in multicellular organisms and in some eukaryotic, single-celled microorganisms such as yeast. Biochemistry, Biochemical events lead to characteristic cell changes (Morphology (biol ...

. Loss of functional endophilin-B1 is seen in many different forms of

cancer Cancer is a group of diseases involving Cell growth#Disorders, abnormal cell growth with the potential to Invasion (cancer), invade or Metastasis, spread to other parts of the body. These contrast with benign tumors, which do not spread. Po ...

. The link between carcinogenesis and dysregulation of cell death pathways suggests that endophilin-B1 serves a critical tumor suppressor role in the cell, although the underlying mechanisms are not known.

Structure

In the presence of model

biological membrane A biological membrane, biomembrane or cell membrane is a selectively permeable membrane that separates the interior of a cell from the external environment or creates intracellular compartments by serving as a boundary between one part of th ...

s, endophilin-B1 dimers assemble into helical scaffolds around the membrane and drive its tubulation.

Interactions

In addition to the membrane binding and remodeling properties endophilin-B1 shares with many other BAR proteins, endophilin-B1 interacts with the pro-apoptotic factor

Bcl-2-associated X protein Apoptosis regulator BAX, also known as bcl-2-like protein 4, is a protein that in humans is encoded by the ''BAX'' gene. ''BAX'' is a member of the Bcl-2 gene family. BCL2 family members form hetero- or homodimers and act as anti- or pro-apopt ...

(Bax) and

SH3GLB2 Endophilin-B2 is a protein that in humans is encoded by the ''SH3GLB2'' gene. Interactions SH3GLB2 has been shown to interact with SH3GLB1 and SH3KBP1 SH3 domain-containing kinase-binding protein 1 (synonyms - CIN85, in rodents - Ruk) is a ...

. It has also been shown to interact with a wide variety of proteins through a canonical

SH3 domain The SRC Homology 3 Domain (or SH3 domain) is a small protein domain of about 60 amino acid residues. Initially, SH3 was described as a conserved sequence in the viral adaptor protein v-Crk. This domain is also present in the molecules of ph ...

that enables PxxP motif-containing protein interactions, including Beclin-1,

amphiphysin Amphiphysin is a protein that in humans is encoded by the ''AMPH'' gene. Function This gene encodes a protein associated with the cytoplasmic surface of synaptic vesicles. A subset of patients with stiff person syndrome who were also affected ...

-1, amphiphysin-2, and

huntingtin Huntingtin (Htt) is the protein coded for in humans by the ''HTT'' gene, also known as the ''IT15'' ("interesting transcript 15") gene. Mutation, Mutated ''HTT'' is the cause of Huntington's disease (HD), and has been investigated for this role an ...

Structure

Interactions

References

Further reading