scholarly journals Analysis of Mason-Pfizer Monkey Virus Gag Domains Required for Capsid Assembly in Bacteria: Role of the N-Terminal Proline Residue of CA in Directing Particle Shape

2000 ◽  
Vol 74 (18) ◽  
pp. 8452-8459 ◽  
Author(s):  
Michaela Rumlova-Klikova ◽  
Eric Hunter ◽  
Milan V. Nermut ◽  
Iva Pichova ◽  
Tomas Ruml
Keyword(s):  
Amino Acid ◽  
Nucleocapsid Protein ◽  
Mammalian Cells ◽  
Matrix Protein ◽  
Amino Acid Residues ◽  
Membrane Expression ◽  
Specific Amino Acid ◽  
Plasma Membrane Expression ◽  
C And N

ABSTRACT Mason-Pfizer monkey virus (M-PMV) preassembles immature capsids in the cytoplasm prior to transporting them to the plasma membrane. Expression of the M-PMV Gag precursor in bacteria results in the assembly of capsids indistinguishable from those assembled in mammalian cells. We have used this system to investigate the structural requirements for the assembly of Gag precursors into procapsids. A series of C- and N-terminal deletion mutants progressively lacking each of the mature Gag domains (matrix protein [MA]-pp24/16-p12-capsid protein [CA]-nucleocapsid protein [NC]-p4) were constructed and expressed in bacteria. The results demonstrate that both the CA and the NC domains are necessary for the assembly of macromolecular arrays (sheets) but that amino acid residues at the N terminus of CA define the assembly of spherical capsids. The role of these N-terminal domains is not based on a specific amino acid sequence, since both MA-CA-NC and p12-CA-NC polyproteins efficiently assemble into capsids. Residues N terminal of CA appear to prevent a conformational change in which the N-terminal proline plays a key role, since the expression of a CA-NC protein lacking this proline results in the assembly of spherical capsids in place of the sheets assembled by the CA-NC protein.

Role of Specific Amino Acid Residues in T4 Endonuclease V That Alter Nontarget DNA Binding†

Biochemistry ◽  
1997 ◽  
Vol 36 (14) ◽  
pp. 4080-4088 ◽  
Author(s):  
Simon G. Nyaga ◽  
M. L. Dodson ◽  
R. Stephen Lloyd
Keyword(s):  
Amino Acid ◽  
Dna Binding ◽  
Amino Acid Residues ◽  
Specific Amino Acid ◽  
Endonuclease V

scholarly journals Role of KLHL3 and dietary K+ in regulating KS-WNK1 expression

2021 ◽  
Author(s):  
Mauricio Ostrosky-Frid ◽  
Maria Chavez-Canales ◽  
Jinwei Zhang ◽  
Olena Andrukova ◽  
Eduardo R. Argaiz ◽  
...  
Keyword(s):  
Amino Acid ◽  
Physiological Role ◽  
Kinase Domain ◽  
Severe Form ◽  
Missense Mutations ◽  
Amino Acid Residues ◽  
Specific Amino Acid ◽  
And Function ◽  
Familial Hyperkalemic Hypertension

The physiological role of the shorter isoform of WNK1 that is exclusively expressed in the kidney (KS-WNK1), with particular abundance in the distal convoluted tubule, remains elusive. KS-WNK1 despite lacking the kinase domain, is nevertheless capable of stimulating the NaCl cotransporter (NCC), apparently through activation of WNK4. It has recently been shown that a less severe form of the Familial Hyperkalemic Hypertension featuring only hyperkalemia is caused by missense mutations in the WNK1 acidic domain that preferentially affect CUL3-KLHL3 E3-induced degradation of KS-WNK1, rather than that of the full-length WNK1 (L-WNK1). Here we show that L-WNK1 is indeed less impacted by the CUL3-KLHL3 E3 ligase complex compared to KS-WNK1. We demonstrate that the unique 30 amino acid amino N-terminal fragment of KS-WNK1 is essential for its activating effect on NCC and recognition by KLHL3. We identify specific amino acid residues in this region critical for the functional effect of KS-WNK1 and KLHL3 sensitivity. To further explore this, we generated KLHL3-R528H knock-in mice that mimic human mutations causing Familial Hyperkalemic Hypertension. These mice revealed that the KLHL3 mutation specifically increased expression of KS-WNK1 in the kidney. We also observed that in wild type mice, expression of KS-WNK1 is only detectable after exposure to low potassium diet. These findings provide new insights into the regulation and function of KS-WNK1 by the CUL3-KLHL3 complex in DCT and indicate that this pathway is regulated by dietary K+ levels.

scholarly journals Identifying and Characterizing a Novel Peritrophic Matrix Protein (MdPM-17) Associated With Antibacterial Response From the Housefly, Musca domestica (Diptera: Muscidae)

2020 ◽  
Vol 20 (6) ◽  
Author(s):  
Yu Wang ◽  
Jinzhi Cheng ◽  
Man Luo ◽  
Jianwei Wu ◽  
Guo Guo
Keyword(s):  
Amino Acid ◽  
Antimicrobial Peptide ◽  
Musca Domestica ◽  
Matrix Protein ◽  
Binding Capacity ◽  
Malpighian Tubule ◽  
Peritrophic Membrane ◽  
Distribution Analysis ◽  
Peritrophic Matrix ◽  
Amino Acid Residues

Abstract Peritrophic matrix/membrane (PM) critically prevents the midgut of insects from external invasion by microbes. The proteins in the peritrophic membrane are its major structural components. Additionally, they determine the formation and function of this membrane. However, the role of PM proteins in immune regulation is unclear. Herein, we isolated a novel PM protein (MdPM-17) from Musca domestica larvae. Further, the function of MdPM-17 in regulating host innate immunity was identified. Results showed that the cDNA of MdPM-17 full is 635 bp in length. Moreover, it consists of a 477-bp open reading frame encoding 158 amino acid residues. These amino acid residues are composed of two Chitin-binding type-2 domain (ChtBD2) and 19 amino acids as a signal peptide. Moreover, tissue distribution analysis indicates that MdPM-17 was enriched expressed in midgut, and moderate levels in the fat body, foregut, and malpighian tubule. Notably, MdPM-17 recombinant protein showed high chitin-binding capacity, thus belongs to the Class III PM protein group. MdPM-17 protein silencing via RNA interference resulted in the expression of antimicrobial peptide (defensin, cecropins, and diptericin) genes, and this occurred after oral inoculation with exogenous microbes Escherichia coli (Enterobacteriales:Enterobacteriaceae), Staphylococcus aureus (Bacillales:Staphylococcaceae), and Candida albicans (Endomycetales:Saccharomycetaceae)). Therefore, all the antimicrobial peptide (AMP) gene expression levels are high in MdPM-17-depleted larvae during microbial infection compared to controls. Consequently, these findings indicate that MdPM-17 protein is associated with the antibacterial response from the housefly.

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