scholarly journals Regulation of clathrin coat assembly by Eps15 homology domain–mediated interactions during endocytosis

2012 ◽  
Vol 23 (4) ◽  
pp. 687-700 ◽  
Author(s):  
Ryohei Suzuki ◽  
Junko Y. Toshima ◽  
Jiro Toshima

Clathrin-mediated endocytosis involves a coordinated series of molecular events regulated by interactions among a variety of proteins and lipids through specific domains. One such domain is the Eps15 homology (EH) domain, a highly conserved protein–protein interaction domain present in a number of proteins distributed from yeast to mammals. Several lines of evidence suggest that the yeast EH domain–containing proteins Pan1p, End3p, and Ede1p play important roles during endocytosis. Although genetic and cell-biological studies of these proteins suggested a role for the EH domains in clathrin-mediated endocytosis, it was unclear how they regulate clathrin coat assembly. To explore the role of the EH domain in yeast endocytosis, we mutated those of Pan1p, End3p, or Ede1p, respectively, and examined the effects of single, double, or triple mutation on clathrin coat assembly. We found that mutations of the EH domain caused a defect of cargo internalization and a delay of clathrin coat assembly but had no effect on assembly of the actin patch. We also demonstrated functional redundancy among the EH domains of Pan1p, End3p, and Ede1p for endocytosis. Of interest, the dynamics of several endocytic proteins were differentially affected by various EH domain mutations, suggesting functional diversity of each EH domain.

2018 ◽  
Vol 201 (4) ◽  
Author(s):  
Fatima C. Pereira ◽  
Filipa Nunes ◽  
Fernando Cruz ◽  
Catarina Fernandes ◽  
Anabela L. Isidro ◽  
...  

ABSTRACTAt a late stage in spore development inBacillus subtilis, the mother cell directs synthesis of a layer of peptidoglycan known as the cortex between the two forespore membranes, as well as the assembly of a protective protein coat at the surface of the forespore outer membrane. SafA, the key determinant of inner coat assembly, is first recruited to the surface of the developing spore and then encases the spore under the control of the morphogenetic protein SpoVID. SafA has a LysM peptidoglycan-binding domain, SafALysM, and localizes to the cortex-coat interface in mature spores. SafALysMis followed by a region, A, required for an interaction with SpoVID and encasement. We now show that residues D10 and N30 in SafALysM, while involved in the interaction with peptidoglycan, are also required for the interaction with SpoVID and encasement. We further show that single alanine substitutions on residues S11, L12, and I39 of SafALysMthat strongly impair binding to purified cortex peptidoglycan affect a later stage in the localization of SafA that is also dependent on the activity of SpoVE, a transglycosylase required for cortex formation. The assembly of SafA thus involves sequential protein-protein and protein-peptidoglycan interactions, mediated by the LysM domain, which are required first for encasement then for the final localization of the protein in mature spores.IMPORTANCEBacillus subtilisspores are encased in a multiprotein coat that surrounds an underlying peptidoglycan layer, the cortex. How the connection between the two layers is enforced is not well established. Here, we elucidate the role of the peptidoglycan-binding LysM domain, present in two proteins, SafA and SpoVID, that govern the localization of additional proteins to the coat. We found that SafALysMis a protein-protein interaction module during the early stages of coat assembly and a cortex-binding module at late stages in morphogenesis, with the cortex-binding function promoting a tight connection between the cortex and the coat. In contrast, SpoVIDLysMfunctions only as a protein-protein interaction domain that targets SpoVID to the spore surface at the onset of coat assembly.


2017 ◽  
Vol 8 (5) ◽  
pp. 903-912 ◽  
Author(s):  
Ainur Sharip ◽  
Diyora Abdukhakimova ◽  
Xiao Wang ◽  
Alexey Kim ◽  
Yevgeniy Kim ◽  
...  

2009 ◽  
Vol 2009 ◽  
pp. 1-17 ◽  
Author(s):  
K. Anamika ◽  
K. R. Abhinandan ◽  
K. Deshmukh ◽  
N. Srinivasan

Protein Kinase-Like Non-kinases (PKLNKs), which are closely related to protein kinases, lack the crucial catalytic aspartate in the catalytic loop, and hence cannot function as protein kinase, have been analysed. Using various sensitive sequence analysis methods, we have recognized 82 PKLNKs from four higher eukaryotic organisms, namely,Homo sapiens,Mus musculus,Rattus norvegicus, andDrosophila melanogaster. On the basis of their domain combination and function, PKLNKs have been classified mainly into four categories: (1) Ligand binding PKLNKs, (2) PKLNKs with extracellular protein-protein interaction domain, (3) PKLNKs involved in dimerization, and (4) PKLNKs with cytoplasmic protein-protein interaction module. While members of the first two classes of PKLNKs have transmembrane domain tethered to the PKLNK domain, members of the other two classes of PKLNKs are cytoplasmic in nature. The current classification scheme hopes to provide a convenient framework to classify the PKLNKs from other eukaryotes which would be helpful in deciphering their roles in cellular processes.


Microbiology ◽  
2006 ◽  
Vol 152 (11) ◽  
pp. 3383-3389 ◽  
Author(s):  
E. Vanterpool ◽  
F. Roy ◽  
W. Zhan ◽  
S. M. Sheets ◽  
L. Sangberg ◽  
...  

The authors have shown previously that the vimA gene, which is part of the bcp-recA-vimA operon, plays an important role in protease activation in Porphyromonas gingivalis. The gingipain RgpB proenzyme is secreted in the vimA-defective mutant P. gingivalis FLL92. An important question that is raised is whether the vimA gene product could directly interact with the proteases for their activation or regulate a pathway responsible for protease activation. To further study the mechanism(s) of VimA-dependent protease activation, the vimA gene product was further characterized. A 39 kDa protein consistent with the size of the predicted VimA protein was purified. In protein–protein interaction studies, the VimA protein was shown to interact with gingipains RgpA, RgpB and Kgp. Immune sera from mice immunized with P. gingivalis immunoreacted with the purified VimA protein. Taken together, these data suggest an interaction of VimA with the gingipains and further confirm the role of this protein in their regulation or maturation.


1984 ◽  
Vol 62 (8) ◽  
pp. 778-788 ◽  
Author(s):  
E. Sackmann ◽  
R. Kotulla ◽  
Franz-Josef Heiszler

The present paper deals with the curvature (or splay) elasticity of lipid bilayers and its possible consequences for the microscopic organization of membranes. Experimental studies of the microstructure of lipid–lipid and lipid–protein mixtures are reported and discussed in terms of this type of membrane elasticity. In particular, evidence is provided that the elastic distortion of lipid bilayers caused by the incorporation of proteins can lead to mechanisms of the indirect protein–protein interaction. Finally the question is discussed whether these mechanisms could also play a role for the formation of enzyme complexes in biological membranes.


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