Thomas Jansen

Nucleotide sequence of cDNA clones encoding the complete ‘23 kDa’ and ‘16 kDa’ precursor proteins associated with the photosynthetic oxygen-evolving complex from spinach

We present the nucleotide sequences and derived amino acid sequences of cDNAs that encode the complete precursors of the extrinsic ‘23 kDa’ and ‘16 kDa’ polypeptides associated with the photosynthetic oxygen‐evolving complex from spinach. The luminal proteins consist of 267/186 (precursor/mature 23 kDa protein) and 232/149 (16 kDa polypeptide) amino acid residues corresponding to molecular masses of 28.5/20.2 and 24.9/16.5 kDa, respectively. Secondary structure predictions disclose epitopes that are potential candidates for two‐step processing of the precursors during import and intraorganelle routing as well as for calcium sequestering, chloride binding and subunit/subunit interaction.

Isolation of cDNA clones for fourteen nuclear-encoded thylakoid membrane proteins

SummarySpinach cDNA libraries, made from polyadenylated seedling RNA, have been constructed in pBR322 and the expression vector λgt11. Recombinant plasmids or phage for 14 intrinsic and peripheral thylakoid membrane proteins and one stromal protein have been identified. They encode components containing antigenic determinants against the lysine-rich 34 kd, the 23 kd and 16 kd proteins all associated with the water-splitting apparatus of the photosystem II reaction center, the ATP synthase subunits gamma, delta and CFo-II, the Rieske Fe/S protein of the cytochrome b/f complex, subunits 2, 3, 5 and 6 of the photosystem I reaction center, plastocyanin, ferredoxin oxidoreductase, chlorophyll a/b-binding apoproteins of the lightharvesting complex associated with photosystem II, and the small subunit of the stromal enzyme ribulose bisphosphate corboxylase/oxygenase. The cDNA inserts lack complementarity to plastid DNA but hybridize to restricted nuclear DNA as well as to discrete poly A+-mRNA species. The precursor products obtained after translation of hybrid selected RNA fractions in a wheat germ assay are imported and processed by isolated unbroken spinach chloroplasts. The imported components comigrate with the respective authentic proteins.

Rosacea: classification and treatment.

Rosacea is a chronic skin disorder affecting the facial convexities, characterized by frequent flushing, persistent erythema, and telangiectases. During episodes of inflammation additional features are swelling, papules and pustules. The disease was originally called acne rosacea, a misleading term that unfortunately persists1. Rosacea is a common disease, especially in fair-skinned people of Celtic and northern European heritage; it has been called the curse of the Celts. It is rare in American and African blacks2. Women are more often affected than men, but they seldom suffer the gross tissue and sebaceous gland hyperplasia of rhinophyma. Onset is usually between ages 30 and 50. In a recent epidemiological study the prevalence was 10%, most of the patients having only a red face3. In young patients especially, there may be a history of acne and the conditions may coexist.

Pathogenesis and Treatment of Acne in Childhood

Abstract: Acne occurs more frequently in newborns and infants than one would gather from written accounts. Acne neonatorum tends to be overlooked because it is usually minor and transient. In contrast, acne infantum, which generally does not make its appearance until after 3 months of life, is more serious. Even acne conglobata may develop in infants. There are many other types of acne in childhood reflecting different pathogenetic mechanisms; included in this group are acne venenata infantum, steroid acne, hormonal disturbances, and toxic reactions.

The complete amino-acid sequence of the Rieske FeS-precursor protein from spinach chloroplasts deduced from cDNA analysis

SummarySummarySeveral cDNA clones encoding the entire Rieske FeS-precursor protein of the chloroplast cytochrome b6f-complex have been isolated by high density plaque immunoscreening of a phage lambda gt11 cDNA expression library, made from poly A+-RNA of spinach seedlings. The identity of the cDNAs has been confirmed by N-terminal amino acid sequencing of the purified protein. The nucleotide sequence indicates a protein of 247 amino acid residues including a putative transit sequence of 68 amino acids corresponding to molecular masses of 26.3 kDa (precursor) and 18.8 kDa (mature protein; 179 amino acid residues). Alignteins of the sequence with sequences from Rieske FeS-proteins of respiratory electron transport chains, two of bacterial and three of mitochondrial origin, shows little sequence homology, but remarkable similarity in secondary structure including a putative N-terminal transmembrane segment of about 25 residues and the peptides CTHLGCV and CPCHGS in the C-terminal region of the protein that are involved in the binding of the Fe2S2-cluster.

Plastocyanin is encoded by an uninterrupted nuclear gene in spinach

SummaryPlastocyanin is a member of photosynthetic electron transport chains that transfers electrons from cytochrome f to the oxidized P700 chlorophyll a pigment of the photosystem I reaction center. We have isolated and characterized cDNA- and genomic clones from spinach (Spinacia oleracea) encoding the complete plastocyanin-precursor polypeptide. The amino acid sequence derived from the nucleotide sequence shows that the precursor consists of 168 amino acid residues including a transit sequence of 69 residues. The precursor polypeptide has a predicted Mr of 16,917, the mature protein of 10,413. The available data indicate that plastocyanin derives probably from a single-copy gene. The coding region contains no intron. The size of the mRNA as determined by S1 nuclease protection experiments is approximately 660 nucleotides, although analysis of different cDNA clones suggests that longer RNA species do exist, approaching the size of the mRNA (850 bases) estimated by Northern blot techniques.

Analysis of cDNA clones encoding the entire precursor-polypeptide for ferredoxin: NADP+ oxidoreductase from spinach

SummaryIn this paper, we report the structural characterization of several spinach ferredoxin-NADP+ oxidoreductase (FNR) cDNAs ranging in size from 0.9 to 1.5 kilobases. A comparison of the deduced amino acid sequence with the known amino acid sequence determined for the spinach protein establishes that 1.4–1.5 kpb inserts span the full length of the mature protein (314 amino acid residues; Mr = 35,382). These also include an N-terminal 55 amino acid transit peptide as well as maximally 171 and 214 nucleotide 5′ and 3′ untranslated sequences, respectively. Evidence has been obtained that various forms of FNR arise from at least two similar genes. The FNR precursor (369 amino acid residues) has a calculated molecular mass of 41.2 kDa. Comparison of the transit peptide with transit peptides from two other stromal proteins shows little similarity at the level of primary sequence but some common features in secondary structure predictions.

Paraneoplastic pemphigus with clinical features of erosive lichen planus associated with Castleman's tumor.

A patient with Castlemans tumor is reported in whom painful mucosal erosions and a maculopapular eruption developed. Complete remission occurred 1 year after surgical tumor resection. The clinical, histological and immunological features were consistent with the syndrome described as paraneoplastic pemphigus.

Diagnosis and Treatment of Rosacea fulminans

Rosacea fulminans is a rare disease of unknown cause which occurs exclusively in women well past adolescence. It was previously called pyoderma faciale because of its confinement to the face covering most of the surface with innumerable fluctuant inflammatory nodules and papules which frequently fuse and form monstrosities. Seborrhea prior to onset is typical. It is not a pyoderma; neither it is infectious or a variant of acne conglobata. The patients respond well to a therapeutic regimen including isotretinoin in combination with topical and systemic corticosteroids. The response is superior and much more rapid than in patients treated with oral antibiotics. Rosacea fulminans is the only indication for topical or systemic corticosteroids in the treatment of rosacea. Scarring is often minimal when the lesions clear. No recurrence is seen.

Progeria Infantum (Hutchinson–Gilford Syndrome) Associated with Scleroderma-Like Lesions and Acro-Osteolysis: A Case Report and Brief Review of the Literature

Abstract: Progeria infantum (Hutchinson–Gilford syndrome) is a very rare syndrome of premature aging characterized by growth retardation and specific, progressive, premature senescent changes of the skin and other tissues. We report a 1.5‐year‐old girl with loss of scalp hair, eyebrows, and lashes, prominent scalp veins, micrognathia, abnormal ears, loss of subcutaneous tissue, and scleroderma‐like areas over the trunk. Radiographic studies revealed coxa valga and acro‐osteolysis of the terminal phalanges. The clinical and radiologic features corresponded well with progeria infantum.