Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hemiparkinsonism-hemiatrophy syndrome (HPHA) is a rare form of parkinsonism, characterized by unilateral parkinsonism, ipsilateral body atrophy and early age of onset. We report a 59-year-old woman with hemiatrophy of her face and upper limb on the left side presenting progressive hemiparkinsonism. Most of the HPHA patients have early age of onset, however, HPHA patients with age of onset over 50 years old have been reported. The clinical features of CBD are partly similar to those of HPHA, therefore it is important to consider HPHA as differential diagnosis of CBD even if the onset is late. In our patient, hemiatrophy was useful to differentiate HPHA from CBD. In previous reports, there was a difference between the dopamine D2 receptor binding capacity of CBD and that of HPHA. While the dopamine D2 receptor binding capacity of CBD was decreased asymmetrically, that of HPHA was not decreased. The PET finding of our patient revealed that asymmetrical reduction of [11C]-CFT uptake, meaning unilateral dopaminergic presynaptic hypofunction. However, [11C]-raclopride uptake, which assesses dopamine D2 receptor binding capacity, was normal. These PET findings are consistent with previous reports on HPHA. In our patient, hemiatrophy and PET findings were useful to diagnose HPHA.
 ...
PMID:[Late onset hemiparkinsonism-hemiatrophy syndrome: a case report]. 1596 Jan 80

A major obstacle to understanding the functional importance of dimerization between class A G protein-coupled receptors (GPCRs) has been the methodological limitation in achieving control of the identity of the components comprising the signaling unit. We have developed a functional complementation assay that enables such control, and we demonstrate it here for the human dopamine D2 receptor. The minimal signaling unit, two receptors and a single G protein, is maximally activated by agonist binding to a single protomer, which suggests an asymmetrical activated dimer. Inverse agonist binding to the second protomer enhances signaling, whereas agonist binding to the second protomer blunts signaling. Ligand-independent constitutive activation of the second protomer also inhibits signaling. Thus, GPCR dimer function can be modulated by the activity state of the second protomer, which for a heterodimer may be altered in pathological states. Our new methodology also makes possible the characterization of signaling from a defined heterodimer unit.
 ...
PMID:Allosteric communication between protomers of dopamine class A GPCR dimers modulates activation. 1969 May 32

We present single photon emission computed tomography (SPECT) studies using 123IFP-CIT (DAT scan) and 123I-IBZM imaging, performed on four members of a family with genetically proven spinocerebellar ataxia type 3 (SCA-3). DAT scan showed significant asymmetric decreased binding in the striatum in the two members with predominant parkinsonian phenotype, with mild and symmetric decreased binding in the member with the cerebellar phenotype, and normal in the asymptomatic member. The IBZM SPECT studies showed mild and asymmetrical reduction of the striatal dopamine D2 receptor density (parkinsonian members). SCA-3 can present with a levodopa responsive parkinsonism phenotype, and an abnormal DAT scan showing predominant impairment of presynaptic dopamine function.
 ...
PMID:Striatal dopamine function in a family with multiple SCA-3 phenotypes. 2080 46