Identification of phostensin, a PP1 F-actin cytoskeleton targeting subunit

Kao, Shu Chen; Chen, Chun Yu; Wang, Shiu Lan; Yang, Jaw Ji; Hung, Wei Chuan; Chen, Yi‐Chen; Lai, Ning‐Sheng; Liu, Hsin Tzu; Huang, Hsien Lu; Chen, Hong Chen; Lin, Ta Hsien; Huang, Hsien Bin

doi:10.1016/j.bbrc.2007.03.026

Cited by 33 publications

(55 citation statements)

References 19 publications

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“…Western blot analysis demonstrated that PT2 only recognizes phostensin in crude proteins extracted from human PBMCs ( Figure 1C). Our analysis predicts that the molecular weight of phostensin is 26 kDa, which is identical to the determination in previous studies in which phostensin was extracted from human PBMCs and recognized by a polyclonal antiphostensin antibody that recognizes residues 144-162 of the protein (Kao et al 2007). …”

Section: Anti-phostensin Monoclonal Antibody Pt2supporting

confidence: 85%

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Immunolocalization of Phostensin in Lymphatic Cells and Tissues

Lin

Huang

Wang

et al. 2011

J Histochem Cytochem.

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SummaryPhostensin binds to the pointed ends of actin filaments and modulates actin dynamics. The genomic location of phostensin is between the HLA-C and HLA-E gene clusters on human chromosome 6, and the mRNA of this protein is predominantly distributed in the spleen, thymus, and peripheral leukocytes. However, the distribution of phostensin in leukocyte cell populations and the subcellular localization have not yet been determined. In this study, an anti-phostensin monoclonal antibody (PT2) that recognizes residues 89-124 of phostensin was prepared and used to examine the subcellular localization and distribution of phostensin in white blood cell populations and in lymphatic tissues. It was found that phostensin is mainly concentrated at the cell periphery and co-localizes with actin filaments. In addition, phostensin was abundant in helper T-lymphocytes, cytotoxic T-lymphocytes, mature monocytes, macrophages, B-lymphocytes, natural killer cells, and granulocytes as well as in the lymphatic tissues, such as the thymus, lymph nodes, and spleen. Phostensin is expressed in the mature lymphocytes of the thymic medulla but not in the immature lymphocytes of the thymic cortex. Taken together, phostensin is a ubiquitous protein in leukocytes, and it may play an important role in modulating the cellular functions of leukocytes. (J Histochem Cytochem 59:741-749, 2011)

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Section: Anti-phostensin Monoclonal Antibody Pt2supporting

confidence: 85%

“…by 5′-RACE, however, only identified a short transcript that encoded a small protein of 165 amino acids (Kao et al, 2007). The primary sequence of this small protein version was identical to the C-terminal region of the predicted larger protein.…”

Section: Discussionmentioning

confidence: 94%

Immunolocalization of Phostensin in Lymphatic Cells and Tissues

Lin

Huang

Wang

et al. 2011

J Histochem Cytochem.

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“…[45, 46] Huang and his group used a rabbit PP1α as bait to screen a human heart cDNA library and found 8 potential interactors, although they only reported 2 of them, both of which were novel proteins, and validated their interaction with PP1 using co-IP, GST pull-down assays, and site-directed mutagenesis. [45, 46] The authors named the first interactor PP1 F-actin cytoskeleton targeting subunit or phostensin ( PPP1R18 ), and found that it co-localized with F-actin and could therefore play a role in targeting PP1c to the F-actin cytoskeleton. [45] The second interactor was named Hepp1 for heart PP1-binding protein and its mRNA was found exclusively in heart and testis by Northern blot.…”

Section: Mapping the Pp1 Interactomementioning

confidence: 99%

“…[45, 46] The authors named the first interactor PP1 F-actin cytoskeleton targeting subunit or phostensin ( PPP1R18 ), and found that it co-localized with F-actin and could therefore play a role in targeting PP1c to the F-actin cytoskeleton. [45] The second interactor was named Hepp1 for heart PP1-binding protein and its mRNA was found exclusively in heart and testis by Northern blot. [46] When the catalytic activity of PP1α was probed in the presence of I-1 and I-2, Hepp1 antagonized the inhibition of both phospho-I-1 and I-2 and non-significantly increased PP1α’s activity on its own.…”

Section: Mapping the Pp1 Interactomementioning

confidence: 99%

Regulating the regulator: Insights into the cardiac protein phosphatase 1 interactome

Chiang

Heck

Dobrev

et al. 2016

Journal of Molecular and Cellular Cardiology

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Reversible phosphorylation of proteins is a delicate yet dynamic balancing act between kinases and phosphatases, the disturbance of which underlies numerous disease processes. While our understanding of protein kinases has grown tremendously over the past decades, relatively little is known regarding protein phosphatases. This may be because protein kinases are great in number and relatively specific in function, and thereby amenable to be studied in isolation, whereas protein phosphatases are much less abundant and more unspecific in their function. To achieve subcellular localization and substrate specificity, phosphatases depend on partnering with a large number of regulatory subunits, protein scaffolds and/or other interactors. This added layer of complexity presents a significant barrier to their study, but holds the key to unexplored opportunities for novel pharmacologic intervention. In this review we focus on the serine/threonine protein phosphatase type-1 (PP1), which plays an important role in cardiac physiology and pathophysiology. Although much work has been done to investigate the role of PP1 in cardiac diseases including atrial fibrillation and heart failure, most of these studies were limited to examining and manipulating the catalytic subunit(s) of PP1 without adequately considering the PP1 interactors, which give specificity to PP1’s functions. To complement these studies, three unbiased methods have been developed and applied to the mapping of the PP1 interactome: bioinformatics approaches, yeast two-hybrid screens, and affinity-purification mass spectrometry. The application of these complementary methods has the potential to generate a detailed cardiac PP1 interactome, which is an important step in identifying novel and targeted pharmacological interventions.

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“…Li et al (2010) also identified a homozygous loss of function mutations in the TPRN gene in affected members of a large consanguineous Moroccan family and a Dutch family DEAFNESS AFTER THE HUMAN GENOME PROJECTwith DFNB79. The taperin protein has similarity to phostensin, an actin filament pointed-end-capping protein reported to modulate the actin cytoskeleton (Kao et al, 2007;Lai et al, 2009). Walsh et al (2010) reported how homozygosity mapping in conjunction with exome sequencing led to the rapid identification of the causative allele for the DFNB82 locus at 1p13.3 in a consanguineous Palestinian family.…”

Section: Nonsyndromic Hlmentioning

confidence: 99%