scholarly journals 2P204 Adaptor transmembrane protein LAT in immune signaling works in vesicles recruited to the plasma membrane : a singlemolecule tracking study(12. Cell biology,Poster)

2013 ◽  
Vol 53 (supplement1-2) ◽  
pp. S192
Author(s):  
Koichiro M. Hirosawa ◽  
Kenta J. Yoshida ◽  
Ankita Chadda ◽  
Kenichi G. N. Suzuki ◽  
Akihiro Kusumi
1984 ◽  
Vol 99 (6) ◽  
pp. 2333-2335 ◽  
Author(s):  
M Edidin ◽  
M Zuniga

We have compared the lateral diffusion of intact transmembrane proteins, wild-type H-2Ld antigens, with that of mutants truncated in the cytoplasmic domain. Diffusion coefficients and mobile fractions were similar for all molecules examined, from wild-type Ld antigens with 31 residues on the cytoplasmic side of the plasma membrane to mutants with only four residues in the cytoplasmic domain. This result limits ways in which the lateral diffusion of a major histocompatibility antigen, a transmembrane protein, can be constrained by interactions with other molecules.


2005 ◽  
Vol 4 (5) ◽  
pp. 911-919 ◽  
Author(s):  
M. Gabriela Roca ◽  
Jochen Arlt ◽  
Chris E. Jeffree ◽  
Nick D. Read

ABSTRACT Although hyphal fusion has been well documented in mature colonies of filamentous fungi, it has been little studied during colony establishment. Here we show that specialized hyphae, called conidial anastomosis tubes (CATs), are produced by all types of conidia and by conidial germ tubes of Neurospora crassa. The CAT is shown to be a cellular element that is morphologically and physiologically distinct from a germ tube and under separate genetic control. In contrast to germ tubes, CATs are thinner, shorter, lack branches, exhibit determinate growth, and home toward each other. Evidence for an extracellular CAT inducer derived from conidia was obtained because CAT formation was reduced at low conidial concentrations. A cr-1 mutant lacking cyclic AMP (cAMP) produced CATs, indicating that the inducer is not cAMP. Evidence that the transduction of the CAT inducer signal involves a putative transmembrane protein (HAM-2) and the MAK-2 and NRC-1 proteins of a mitogen-activated protein kinase signaling pathway was obtained because ham-2, mak-2, and nrc-1 mutants lacked CATs. Optical tweezers were used in a novel experimental assay to micromanipulate whole conidia and germlings to analyze chemoattraction between CATs during homing. Strains of the same and opposite mating type were shown to home toward each other. The cr-1 mutant also underwent normal homing, indicating that cAMP is not the chemoattractant. ham-2, mak-2, and nrc-1 macroconidia did not attract CATs of the wild type. Fusion between CATs of opposite mating types was partially inhibited, providing evidence of non-self-recognition prior to fusion. Microtubules and nuclei passed through fused CATs.


2021 ◽  
Vol 90 (1) ◽  
Author(s):  
Yi Wen ◽  
Volker M. Vogt ◽  
Gerald W. Feigenson

Located at the inner leaflet of the plasma membrane, phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] comprises only 1–2 mol% of total PM lipids. With its synthesis and turnover both spatially and temporally regulated, PI(4,5)P2 recruits and interacts with hundreds of cellular proteins to support a broad spectrum of cellular functions. Several factors contribute to the versatile and dynamic distribution of PI(4,5)P2 in membranes. Physiological multivalent cations such as Ca2+ and Mg2+ can bridge between PI(4,5)P2 headgroups, forming nanoscopic PI(4,5)P2–cation clusters. The distinct lipid environment surrounding PI(4,5)P2 affects the degree of PI(4,5)P2 clustering. In addition, diverse cellular proteins interacting with PI(4,5)P2 can further regulate PI(4,5)P2 lateral distribution and accessibility. This review summarizes the current understanding of PI(4,5)P2 behavior in both cells and model membranes, with emphasis on both multivalent cation– and protein-induced PI(4,5)P2 clustering. Understanding the nature of spatially separated pools of PI(4,5)P2 is fundamental to cell biology. Expected final online publication date for the Annual Review of Biochemistry, Volume 90 is June 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


2011 ◽  
Vol 51 (supplement) ◽  
pp. S93-S94
Author(s):  
Koichiro M. Hirosawa ◽  
Kenta J. Yoshida ◽  
Kenichi G. N. Suzuki ◽  
Takahiro K. Fujiwara ◽  
Ankita Chadda ◽  
...  

2020 ◽  
Author(s):  
Matthieu Bourdon ◽  
Josephine Gaynord ◽  
Karin Müller ◽  
Gareth Evans ◽  
Simon Wallis ◽  
...  

AbstractDionysia tapetodes, a small cushion-forming mountainous evergreen in the Primulaceae, possesses a vast surface-covering of long silky fibres forming the characteristic “wooly” farina. This contrasts with some related Primula which instead possess a powdery farina. Using a combination of cell biology and analytical chemical techniques, we provide a detailed insight of wooly farina formation by glandular trichomes that produce a mixture of flavone and substituted flavone derivatives, including hydroxyflavones. Conversely, our analysis show that the powdery form consist almost entirely of flavone. The wooly farina in D. tapetodes is extruded through specific sites at the surface of the glandular head cell, characterised by a small complete gap in the plasma membrane, cell wall and cuticle. The data is consistent with formation and thread elongation occurring from within the cell. The putative mechanism of wool thread formation and its stability is discussed.


2018 ◽  
Author(s):  
Yunxiao Zhang ◽  
David P. Bulkley ◽  
Kelsey J. Roberts ◽  
Yao Xin ◽  
Daniel E. Asarnow ◽  
...  

AbstractHedgehog protein signals mediate tissue patterning and maintenance via binding to and inactivation of their common receptor Patched, a twelve-transmembrane protein that otherwise would suppress activity of the seven-transmembrane protein, Smoothened. Loss of Patched function, the most common cause of basal cell carcinoma, permits unregulated activation of Smoothened and of the Hedgehog pathway. A cryo-EM structure of the Patched protein reveals striking transmembrane domain similarities to prokaryotic RND transporters. The extracellular domain mediates association of Patched monomers in an unusual dimeric architecture that implies curvature in the associated membrane. A central conduit with cholesterol-like contents courses through the extracellular domain and resembles that used by other RND proteins to transport substrates, suggesting Patched activity in cholesterol transport. Patched expression indeed reduces cholesterol activity in the inner leaflet of the plasma membrane, in a manner antagonized by Hedgehog stimulation and with implications for regulation of Smoothened.


2018 ◽  
Vol 19 (9) ◽  
pp. 2572 ◽  
Author(s):  
Chen Su ◽  
Kai Chen ◽  
Qingqian Ding ◽  
Yongying Mou ◽  
Rui Yang ◽  
...  

The plasma membrane is the first subcellular organ that senses low temperature, and it includes some spanning transmembrane proteins that play important roles in cold regulation. COR413-PM1 is a novel multispanning transmembrane cold-regulated protein; however, the related functions are not clear in Arabidopsis. We found the tolerance to freezing stress of cor413-pm1 was lower than wild-type (WT). A proteomics method was used to analyze the differentially abundant proteins (DAPs) between cor413-pm1 and WT. A total of 4143 protein groups were identified and 3139 were accurately quantitated. The DAPs associated with COR413-PM1 and freezing treatment were mainly involved in the metabolism of fatty acids, sugars, and purine. Quantitative real-time PCR (qRT-PCR) confirmed the proteomic analysis results of four proteins: fatty acid biosynthesis 1 (FAB1) is involved in fatty acid metabolism and might affect the plasma membrane structure; fructokinase 3 (FRK3) and sucrose phosphate synthase A1 (SPSA1) play roles in sugar metabolism and may influence the ability of osmotic adjustment under freezing stress; and GLN phosphoribosyl pyrophosphate amidotransferase 2 (ASE2) affects freezing tolerance through purine metabolism pathways. In short, our results demonstrate that the multispanning transmembrane protein COR413-PM1 regulates plant tolerance to freezing stress by affecting the metabolism of fatty acids, sugars, and purine in Arabidopsis.


Development ◽  
1991 ◽  
Vol 111 (4) ◽  
pp. 1021-1028 ◽  
Author(s):  
C. Hashimoto ◽  
S. Gerttula ◽  
K.V. Anderson

Formation of the Drosophila embryo's dorsal-ventral pattern requires the maternal product of the Toll gene. DNA sequence and genetic analyses together suggested that the Toll gene product is a transmembrane protein which communicates information from an extracytoplasmic compartment to the cytoplasm. Using antibodies as probes, we show that the Toll protein is a 135 × 10(3) Mr glycoprotein which is tightly associated with embryonic membranes. During the syncytial stage when dorsal-ventral polarity is established, the maternal Toll protein is associated with the plasma membrane around the entire embryo. During later embryonic stages, the Toll protein is expressed zygotically on many cell surfaces, possibly to promote cell adhesion. The plasma membrane localization of the Toll protein in the syncytial embryo suggests that transmembrane signaling from the extracellular perivitelline space to the cytoplasm is required for establishment of the embryonic dorsal-ventral pattern.


2019 ◽  
Vol 316 (6) ◽  
pp. C805-C814 ◽  
Author(s):  
Subrata Sabui ◽  
Veedamali S. Subramanian ◽  
Quang Pham ◽  
Hamid M. Said

The apically localized riboflavin (RF) transporter-3 (RFVT-3) is involved in intestinal absorption of vitamin B2. Previous studies have characterized different physiological/biological aspects of the RFVT-3, but there is a lack of knowledge regarding possible existence of interacting partner(s) and consequence of interaction(s) on its function/cell biology. To address the latter, we performed yeast two-hybrid (Y2H) screening of a human colonic cDNA library and have identified transmembrane protein 237 (TMEM237) as a putative interactor with the human (h)RFVT-3; the interaction was further confirmed via “1-by-1” Y2H assay that involved appropriate positive and negative controls. TMEM237 was found to be highly expressed in human native intestine and in human intestinal epithelial cell lines; further, confocal images showed colocalization of the protein with hRFVT-3. The interaction between TMEM237 with hRFVT-3 in human intestinal epithelial HuTu-80 cells was established by coimmunoprecipitation. Expressing TMEM237 in HuTu-80 cells led to a significant induction in RF uptake, while its knockdown (with the use of gene-specific siRNA) led to a significant reduction in uptake. Transfecting TMEM237 into HuTu-80 cells also led to a marked enhancement in hRFVT-3 protein stability (reflected by an increase in the protein half-life). Interestingly, the level of expression of TMEM237 was found to be markedly reduced following treatment with TNF-α (a proinflammatory cytokine that inhibits intestinal RF uptake), while its expression was significantly upregulated following treatment with butyrate (an inducer of intestinal RF uptake). These findings identify TMEM237 as an interactor with the intestinal hRFVT-3 and show that the interaction has physiological/biological significance.


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