Blair stepped in front of Santiago’s cell door, saying, “things are going to get worse.” Whether these conditions and this statement are themselves a constitutional violation is irrelevant. A prisoner has the “right under the First Amendment to petition for redress of grievances under a prison’s grievance procedures[,]” Nelson, 603 F.3d at 449, and “conduct that retaliates against the exercise of a constitutionally protected right ... is actionable even if the alleged retaliatory conduct does not itself rise to the level of a constitutional violation[,]” Van Wyhe v. Reisch, 581 F.3d 639, 658 (8th Cir.2009). We have held that deprivations and threats such as those allegedly made by Blair are sufficient to support a First Amendment retaliation claim. See, e.g., Nelson, 603 F.3d at 450 (<HOLDING>); Cooper, 189 F.3d at 784 (allegation that the
holding that appellant had submitted sufficient evidence of racebased retaliation to survive summary judgment on his  1981 claim holding that the plaintiff who allegedly was held in isolation in a structurally unfinished and inadequate ward and deprived of access to legal counsel mail family recreation and phone calls had demonstrated sufficient deprivations to survive summary judgment on a first amendment retaliation claim holding that the first amendment right of access applies to a summary judgment motion in a civil case recognizing first amendment retaliation right holding without discussing the plaintiffs burden of persuasion that the plaintiff had presented sufficient evidence to survive summary judgment