Vocational implications of post-polio syndrome.

Of more than 1,000,000 survivors of poliomyelitis living in the United States, about 80% experience symptoms associated with post-polio syndrome (PPS). New weakness, fatigue, and pain are the most common symptoms that may appear years after acute polio. PPS is reported to be the most prevalent progressive neuromuscular disease in North America.

Red light-induced accumulation of ubiquitin-phytochrome conjugates in both monocots and dicots.

Phytochrome is rapidly degraded in vivo after photoconversion from the stable red-absorbing (Pr) form to the far red-absorbing (Pfr) form. Previously, we have shown in etiolated oat seedlings that ubiquitin-phytochrome conjugates (Ub-P) appear after Pfr formation suggesting that oat phytochrome is rapidly degraded by a ubiquitin-dependent proteolytic pathway. Here, we extend this observation to etiolated tissue from other monocotyledonous (corn [Zea mays.

Ubiquitin-phytochrome conjugates. Pool dynamics during in vivo phytochrome degradation.

The plant photoreceptor chromoprotein, phytochrome, is rapidly degraded in vivo after photoconversion from a stable red light-absorbing form (Pr) to a far-red light-absorbing form (Pfr). Previously, we demonstrated that during Pfr degradation in etiolated oat seedlings, ubiquitin-phytochrome conjugates, (Ub-P), appear and disappear suggesting that phytochrome is degraded via a ubiquitin-dependent proteolytic pathway (Shanklin, J., Jabben, M.

Red light-induced formation of ubiquitin-phytochrome conjugates: Identification of possible intermediates of phytochrome degradation.

Phytochrome is the photoreceptor that controls red light-mediated morphogenesis in higher plants. It exists in two photointerconvertible forms, a red light-absorbing form, Pr, and a far-red light-absorbing form, Pfr. Because photoconversion of Pr to Pfr by a brief light pulse decreases the in vivo half-life of this chromoprotein by a factor of approximately 100, this system offers a unique way to modulate the turnover rate of a specific protein and hence study the mechanisms responsible for selective protein degradation.

Phase Shift in the Circadian Rhythm of Floral Promotion by Far Red Energy in Hordeum vulgare L.

Eight-day-old barley seedlings (Hordeum vulgare L. cv. Wintex) were pretreated with a single 24-hour daylight fluorescent photoperiod that was supplemented with sufficient far-red energy (FR) to produce a relative red (R)/FR ratio of 0.